CNL-14-132, Third Six-Month Status Report and Revised Overall Integrated Plan in Response to the March 12, 2012, Commission Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events for Bro
ML14248A496 | |
Person / Time | |
---|---|
Site: | Browns Ferry ![]() |
Issue date: | 08/28/2014 |
From: | James Shea Tennessee Valley Authority |
To: | Document Control Desk, Office of Nuclear Reactor Regulation |
References | |
CNL-14-132, EA-12-049, TAC MF0902, TAC MF0903, TAC MF0904 L44 140828 008 | |
Download: ML14248A496 (100) | |
Text
L44 140828 008 Tennessee Valley Authority, 1101 Market Street, Chattanooga, Tennessee 37402 CNL-14-132 August 28, 2014 10 CFR 2.202 10 CFR 50.4 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 Browns Ferry Nuclear Plant, Units 1, 2, and 3 Facility Operating License Nos. DPR-33, DPR-52, and DPR-68 NRC Docket Nos. 50-259, 50-260, and 50-296
Subject:
Third Six-Month Status Report and Revised Overall Integrated Plan in Response to the March 12, 2012, Commission Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events (Order Number EA-12-049) for Browns Ferry Nuclear Plant (TAC Nos. MF0902, MF0903, and MF0904)
References:
- 1. NRC Order Number EA-12-049, Issuance of Order to Modify Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events, dated March 12, 2012 (ML12054A735)
- 2. NRC Interim Staff Guidance JLD-ISG-2012-01, Compliance with Order EA 049, Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events, Revision 0, dated August 29, 2012 (ML12229A174)
Implementation Guide, Revision 0, dated August 2012 (ML12242A378)
- 4. Letter from TVA to NRC, Tennessee Valley Authority (TVA) - Initial Status Report in Response to the March 12, 2012, Commission Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events (Order Number EA-12-049),
dated October 29, 2012 (ML12307A104)
U.S. Nuclear Regulatory Commission Page 2 August 28, 2014
- 5. Letter from TVA to NRC, Tennessee Valley Authority (TVA) - Overall Integrated Plan in Response to the March 12, 2012, Commission Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events (Order Number EA-12-049) for Browns Ferry Nuclear Plant, dated February 28, 2013 (ML13064A465)
- 6. Letter from TVA to NRC, First Six-Month Status Report in Response to the March 12, 2012, Commission Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events (Order Number EA-12-049) for Browns Ferry Nuclear Plant, dated August 28, 2013 (ML13247A284)
- 7. Letter from NRC to TVA, Browns Ferry Nuclear Plant, Units 1, 2, and 3 -
Interim Staff Evaluation Relating to Overall Integrated Plan in Response to Order EA-12-049 (Mitigation Strategies) (TAC Nos. MF0902, MF0903, and MF0904), dated December 19, 2013 (ML13353A166)
- 8. Letter from TVA to NRC, Second Six-Month Status Report in Response to the March 12, 2012, Commission Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events (Order Number EA-12-049) for Browns Ferry Nuclear Plant (TAC Nos. MF0902, MF0903, and MF0904), dated February 28, 2014 (ML14064A240)
On March 12, 2012, the Nuclear Regulatory Commission (NRC) issued an order (Reference 1) to Tennessee Valley Authority (TVA). Reference 1 was immediately effective and directed TVA to develop, implement, and maintain guidance and strategies to maintain or restore core cooling, containment, and spent fuel pool cooling capabilities following a beyond-design-basis external event. Specific requirements are outlined in Attachment 2 of Reference 1.
Reference 1 required submission of an initial status report 60 days following issuance of the final interim staff guidance (Reference 2) and an overall integrated plan pursuant to Section IV, Condition C. Reference 2 endorses industry guidance document Nuclear Energy Institute (NEI) 12-06, Revision 0 (Reference 3) with clarifications and exceptions identified in Reference 2. Reference 4 provided the TVA initial status report regarding mitigation strategies. Reference 5 provided the TVA Browns Ferry Nuclear Plant, Units 1, 2, and 3 overall integrated plan.
Reference 1 requires submission of a status report at six-month intervals following submittal of the overall integrated plan. Reference 3 provides direction regarding the content of the status reports. TVA provided the first six-month status report on August 28, 2013 (Reference 6). The NRC issued its Interim Staff Evaluation regarding TVAs overall integrated plan on December 19, 2013 (Reference 7). TVA submitted its second six-month status report on February 28, 2014 (Reference 8).
U.S. Nuclear Regulatory Commission Page 3 August 28, 2014 In Section 7 to the Enclosure of Reference 8, it was noted that TVA was evaluating potential changes to the capacity and storage options of the current 3 MW FLEX diesels and the potential need for relief regarding Order EA-12-049 FLEX/Order EA-13-109 containment venting interface. Reference 8 also noted any changes to the BFN mitigation strategies resulting from this review would be provided to the NRC in the third six-month status report.
The purpose of this letter is to provide the third six-month status report pursuant to Section IV, Condition C.2, of Reference 1, that delineates progress made in implementing the requirements of Reference 1, including the resulting changes to the capacity and storage options of the current 3 MW FLEX diesels. Specifically, the Enclosure of this letter provides a revised Overall Integrated Plan (OIP) and it replaces the OIP submitted in Reference 2 in its entirety. Revision 1 of the OIP incorporates the following changes from Revision 0.
x Use of pre-staged 225kva and 3MW diesel generators has been revised to use of portable 850kw and 1.1MW generators stored in the FLEX Equipment Storage Building (FESB);
x Revision to the following strategies due to change from pre-staged 225kva and 3 MW diesel generators to portable 850kw and 1.1MW generators:
o electrical connection strategies, o load shed strategies, o FLEX generator re-fueling and staging strategies, o Phase 2 spent fuel pool makeup strategy; and, o Sequence of Events; x Use of Residual Heat Removal (RHR) system for decay heat removal has been revised to use of hardened wetwell vent as primary strategy to provide containment cooling; and, x Incorporation of changes noted in the first and second 6-month status reports submitted in References 6 and 8.
In addition to the changes described above, the Open Items table in the Enclosure has been updated. The milestone target completion dates have also been updated as shown in of the Enclosure.
Because the wetwell vent will be used as the primary strategy to provide containment cooling, TVA has determined that relief regarding Order EA-12-049 FLEX and Order EA-13-109 containment venting interface is needed. TVA is submitting, under separate letter, a Request for Relaxation from NRC Order EA-12-049 in parallel with this six-month status report. TVAs Request for Relaxation follows previously submitted Boiling Water Reactor industry precedents.
U.S. Nuclear Regulatory Commission Page 4 August 28, 2014 The Enclosure describes the plans that TVA will use to meet the regulatory requirements outlined in Attachment 2 of Reference 1, but does not identify any additional actions to be taken by TVA. Therefore, this letter contains no regulatory commitments.
If you have any question regarding this submittal, please contact Kevin Casey at (423) 751-8523.
I declare under penalty of perjury that the foregoing is true and correct. Executed on the 28th day of August 2014.
Respectfully, Digitally signed by J. W. Shea DN: cn=J. W. Shea, o=Tennessee J. W. Shea Valley Authority, ou=Nuclear Licensing, email=jwshea@tva.gov, c=US Date: 2014.08.28 20:05:42 -04'00' J. W. Shea Vice President, Nuclear Licensing
Enclosure:
Tennessee Valley Authority Browns Ferry Nuclear Plant, Mitigation Strategies for Beyond-Design-Basis External Events Overall Integrated Plan, Revision 1 cc (Enclosure):
NRR Director - NRC Headquarters NRO Director - NRC Headquarters NRR JLD Director - NRC Headquarters NRC Regional Administrator - Region II NRC Project Manager - Browns Ferry Nuclear Plant NRC Senior Resident Inspector - Browns Ferry Nuclear Plant
ENCLOSURE TENNESSEE VALLEY AUTHORITY BROWNS FERRY NUCLEAR PLANT MITIGATION STRATEGIES FOR BEYOND-DESIGN-BASIS EXTERNAL EVENTS OVERALL INTEGRATED PLAN REVISION 1
General Integrated Plan Elements (PWR & BWR)
(Section 1) Determine Input the hazards applicable to the site; seismic, external Applicable Extreme External flood, high winds, snow, ice, cold, high temps.
Hazard Describe how NEI 12-06 sections 5 - 9 were applied and the basis for why the plant screened out for certain Ref: NEI 12-06, section 4.0 -9.0 hazards.
JLD-ISG-2012-01, section 1.0 The Browns Ferry Nuclear Plant (BFNP) site has been evaluated using the Nuclear Energy Institute (NEI) Flexible and Diverse Coping Mitigation Strategies (FLEX) guidance and the following applicable hazards have been identified:
- seismic events,
- external flooding,
- storms with high winds and tornadoes,
- snow, ice, extreme cold and
- extreme heat.
Browns Ferry Nuclear Plant has determined the functional threats from each of these hazards and identified FLEX equipment that may be affected. The FLEX equipment and FLEX strategies consider the impacts of the applicable external hazards and will address protection and deployment of FLEX equipment, procedural interfaces, and utilization of on-site and off-site resources.
Seismic Hazard Assessment Per NEI 12-06, seismic hazards must be considered for all nuclear sites. As a result, the credited FLEX equipment will be assessed based on current BFNP seismic licensing basis to ensure that the equipment remains accessible and available after a Beyond-Design-Basis External Event (BDBEE) and that the FLEX equipment does not become a target or source of a seismic interaction from other systems, structures, or components (Open Item, OI 9). Per the BFNP Units 1, 2, and 3 Updated Final Safety Analysis Reports (UFSAR) section 2.5 (Ref. 1d) for a Design Basis Earthquake (DBE) / Safe Shutdown Earthquake (SSE) the maximum rock acceleration requirements are 0.2g horizontal and 0.133g vertical. For an Operating Basis Earthquake (OBE), the maximum horizontal and vertical ground accelerations are 0.1g and 0.067g. The FLEX strategies developed for BFNP will include documentation ensuring that any storage locations and deployment routes meet the FLEX seismic criteria (Open Item, OI 14).
Liquefaction The liquefaction potential of FLEX deployment routes from Staging area B to Staging Area A, refer to Attachment 3 - Figure 5 for conceptual sketch of staging areas that will be evaluated in a future assessment (Open Item, OI 2). An evaluation will be performed of the route(s) from Staging Area D and Staging Area C to Staging Area B (Open Item, OI 2).
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Internal Flooding Abnormal operating procedure, AOI-100-9, Turbine Building Internal Flooding, provides the symptoms and operator actions to be taken for this condition. During development of procedures to support FLEX strategies, adequate guidance will be given to operators to ensure their travel paths avoid these areas. (OI 21)
External Flooding Hazard Assessment Browns Ferry Nuclear Plant is susceptible to flooding via two sources:
x local intense precipitation and x river flooding.
The Probable Maximum Flood (PMF) will reach a maximum still-water elevation of 572.5',
per UFSAR section 2.4A (Ref. 1c). A maximum flood elevation of 578' at BFNP results from a combination of the PMF and wind wave run-up on a vertical wall per UFSAR (Ref. 1c).
Plant grade is at elevation 565 and Browns Ferry Nuclear Plant structures, located in the flood plain which house equipment important to safety are designed to remain watertight by utilizing both permanently installed and temporary barriers (wet site). The maximum duration flood at BFNP lasts 10.5 days above plant grade and reaches a maximum still water elevation of 569.2 feet. The FLEX strategies developed for BFNP will ensure that any storage locations, deployment routes, and connection points meet the FLEX flooding criteria, are at an elevation not susceptible to flooding (except for those strategy elements not credited for flooding) or deployment and connection is completed during the timeframe from level rising from elevation 558 to 565 (approximately 5 days). In addition, BFNP is also developing procedures and strategies for delivery of offsite FLEX equipment during Phase 3 which considers regional impacts from flooding (Open Item, OI 14).
Storms with High Winds and Tornadoes Hazards Assessment NEI 12-06 Figures 7-1 and 7-2 were used for this assessment.
Browns Ferry Nuclear Plant is susceptible to hurricanes, as the plant is within the contour lines shown in NEI 12-06 Figure 7-1 (Ref. 3a).
It was determined that BFNP site has the potential to experience damaging winds caused by tornado exceeding 130 mph. Figure 7-2 of NEI 12-06 indicates a maximum wind speed of 200 mph for Region 1 plants, including BFNP. Therefore, high-wind hazards are applicable to BFNP. It should be noted that BFNP was designed to 300 mph wind loads.
In summary, based on available local data and NEI 12-06 Figures 7-1 and 7-2 (Ref. 3a & 3b)
BFNP is susceptible to severe storms with high winds so the hazard is considered to be credible.
Snow, Ice, and Extreme Cold Hazards Assessment Per NEI 12-06 (Ref. 3) all sites should consider the temperature ranges and weather conditions for their site in storing and deploying their FLEX equipment. Equipment procured should be suitable for use in the anticipated range of conditions for the site, consistent with normal design practices.
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(Section 1) Determine Applicable Extreme External Hazard Ref: NEI 12-06, section 4.0 -9.0 JLD-ISG-2012-01, section 1.0 Applicability of snow and extreme cold As depicted in NEI 12-06 Figure 8-1 (Ref. 3c) for plants located below the 35th parallel, snow and extreme cold events are unlikely to present a significant problem for deployment of FLEX.
Browns Ferry Nuclear Plant is below the 35th parallel; however, based on historical data collected from both NEI 12-06 Figure 8-1 (Ref. 3c) and the BFNP UFSAR, snowfalls in excess of 6 inches have occurred in the past. Browns Ferry Nuclear Plant UFSAR section 2.3.5.3 (Ref. 1b) references snowfall reports of 17.1, 10.1, and 10.0 inches near BFNP. Per UFSAR section 2.3.5.1 (Ref. 1a), in a typical year, Decatur, Alabama (located approximately 10 miles southeast of BFNP) has approximately 57 days per year with minimum temperatures equal to or less than 32°F with an extreme daily temperature record of -12°F. Therefore, the FLEX strategies will consider the challenges caused by extreme snowfall and extremely cold temperatures.
Applicability of ice storms Browns Ferry Nuclear Plant is located in either ice severity level 4 or 5 region, defined by NEI 12-06 Figure 8-2 (Ref. 3d). Browns Ferry Nuclear Plant FLEX strategies will consider impedances caused by ice storms.
In summary, based on the available local data and NEI 12-06, Figures 8-1 and 8-2 (Ref. 3c &
3d) BFNP does experience significant amounts of snow, ice, and extreme cold temperatures; therefore, the hazards are considered to be credible.
Extreme Heat Per NEI 12-06 (Ref. 3) all sites must address high temperatures. Virtually every state in the lower 48 contiguous United States has experienced temperatures in excess of 110°F. Many states have experienced temperatures in excess of 120°F. Per the UFSAR section 2.3.5.1, in a typical year, Decatur, Alabama (located approximately 10 miles southeast of BFNP) has approximately 70 days per year with maximum temperatures equal to or greater than 90°F, with an extreme daily temperature record of 108°F.
Selection of BFNP FLEX equipment will consider the site maximum expected temperatures in their specification, storage, and deployment requirements, including adequate ventilation or supplementary cooling, as required.
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(Section 1) Determine Applicable Extreme External Hazard Ref: NEI 12-06, section 4.0 -9.0 JLD-ISG-2012-01, section 1.0
References:
- 1. Browns Ferry Nuclear Plant (BFNP) Updated Final Safety Analysis Report (UFSAR)
- a. Section 2.3.5.1
- b. Section 2.3.5.3
- c. Section 2.4
- d. Section 2.5
- 2. Draft Interim Staff Guidance JLD-ISG-2012-01, Compliance with Order EA-12-049, Order Modifying Licenses with Regard to Requirements for Mitigating Strategies for Beyond-Design-Basis External Events; Docket ID NRC-2012-0068
- a. Figure 7-1
- b. Figure 7-2
- c. Figure 8-1
- d. Figure 8-2
- 4. BFN calculation CDQ000020080054 Rev. 4, Nuclear PMF Determination for Tennessee River Watershed Notes:
None Page 5 of 96
(Section 2) Key Site Provide key assumptions associated with implementation of assumptions to implement NEI FLEX Strategies:
12-06 strategies. x Flood and seismic re-evaluations pursuant to the 10 CFR 50.54(f) letter of March 12, 2012 are not Ref: NEI 12-06, section 3.2.1 completed and therefore, not assumed in this submittal. As the re-evaluations are completed, appropriate issues will be entered into the corrective action system and addressed on a schedule commensurate with other licensing bases changes.
x Exceptions for the site security plan or other (license/site specific) requirements of 10CFR may be required.
x Deployment resources are assumed to begin arriving at hour 6 and fully staffed by 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
x Certain Technical Specifications cannot be complied with during FLEX implementation.
Key assumptions associated with implementation of Flexible and Diverse Coping Mitigation Strategies (FLEX) Strategies for Browns Ferry Nuclear Plant (BFNP) are described below:
Flood and seismic re-evaluations pursuant to the 10 CFR 50.54(f) letter of March 12, 2012 (Ref. 1) are not completed and therefore, not assumed in this submittal. As the re-evaluations are completed, appropriate issues will be entered into the corrective action program and addressed on a schedule commensurate with other licensing bases changes. (Open Item, OI 1).
x The following conditions exist for the baseline case:
o Seismically designed DC battery banks are available; o Seismically designed AC and DC distribution panels are available; o Plant initial response is the same as for Station Blackout (SBO);
o Best estimate analysis and decay heat is used to establish requirements for operator time and action; o System, Structure, or Component (SSC) failures that are random or due to causes beyond those stipulated in the Order are not assumed.
x Margin will be added to design FLEX components and hard connection points to address future requirements as re-evaluation warrants. Portable FLEX components will be procured commercially.
x The design hardened connections shall be protected against external events or are established at multiple and diverse locations.
x Deployment strategies and deployment routes are assessed for impact due to identified hazards (Open Item, OI 14).
x Phase 2 FLEX components are stored at the site and available after the event they are designed to mitigate.
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(Section 2) Key Site assumptions to implement NEI 12-06 strategies.
Ref: NEI 12-06, section 3.2.1 x Additional staff resources are expected to begin arriving at 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and the site will be fully staffed 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> after the event. (Ref. 2) x Exceptions for the site security plan or other (license/site specific) requirements may be identified during the design process. These exceptions will be processed when they are identified.
x FLEX assumes that:
(1) On-site staff are at site administrative minimum shift staffing levels (minimum staffing may include additional staffing that is procedurally brought on-site in advance of a predicted external event, e.g., hurricane or flood);
(2) There are no independent, concurrent events, e.g., no active security threat; (3) All personnel on-site are available to support site response (including Security, etc.).
The normal emergency response capabilities are augmented by NEI 12-01 (Ref. 4).
Staffing will continue to be developed further as the design phase for FLEX progresses.
(Open Item, OI 15) x Though specific strategies are being developed, due to the inability to anticipate all possible scenarios, the strategies are also diverse and flexible to encompass a wide range of possible conditions. These pre-planned strategies developed to protect the public health and safety will be incorporated into the unit Operating Procedures in accordance with established procedure change processes, and their impact to the design basis capabilities of the unit evaluated under 10 CFR 50.59. (Open Item, OI 17) The plant Technical Specifications contain the limiting conditions for normal unit operations to ensure that design safety features are available to respond to a design basis accident and direct the required actions to be taken when the limiting conditions are not met. Per Final Response to Task Interface Agreement (TIA) 2004-04 (Ref. 3) the result of the beyond-design-basis event may place the plant in a condition where it cannot comply with certain Technical Specifications, and as such, may warrant invocation of 10 CFR 50.54(x) and/or 10 CFR 73.55(p).
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(Section 2) Key Site assumptions to implement NEI 12-06 strategies.
Ref: NEI 12-06, section 3.2.1
References:
- 2. BWR Owners Group - Emergency Procedure and Severe Accident Guidelines, Revision 3 (February 2013)
- 3. Final Response to Task Interface Agreement (TIA) 2004-04, Acceptability of Proceduralized Departures from Technical Specifications (TSs) Requirements at the Surry Power Station, (TAC Nos. MC4331 and MC4332), dated September 12, 2006 (Accession No. ML060590273)
- 4. NEI 12-01, Guideline for Assessing Beyond-Design-Basis Accident Response Staffing and Communications Capabilities
None Page 8 of 96
Section 3) Extent to which the Include a description of any alternatives to the guidance, guidance, JLD-ISG-2012-01 and and provide a milestone schedule of planned action.
NEI 12-06, are being followed.
Identify any deviations to JLD-ISG-2012-01 and NEI 12-06.
Ref: JLD-ISG-2012-01 NEI 12-06, section 13.1 Browns Ferry Nuclear Plant has no known deviations to the guidelines in JLD-ISG-2012-01 (Ref. 1) and NEI 12-06 (Ref. 2). If deviations are identified, then the deviations will be communicated in a future 6 month update following identification.
References:
- 1. Draft Interim Staff Guidance JLD-ISG-2012-01, Compliance with Order EA-12-049, Order Modifying Licenses with Regard to Requirements for Mitigating Strategies for Beyond-Design-Basis External Events; Docket ID NRC-2012-0068
None Page 9 of 96
(Section 4) Provide a Strategies that have a time constraint to be successful should be sequence of events identified with a technical basis and a justification provided that the and identify any time time can reasonably be met (for example, a walkthrough of constraint required deployment).
for success including the technical basis for Describe in detail in this section the technical basis for the time the time constraint. constraint identified on the sequence of events timeline Attachment 1A Ref: NEI 12-06, section 3.2.1.7 See attached sequence of events timeline (Attachment 1A).
JLD-ISG-2012-01, section Technical Basis Support information, see attached NSSS Significant 2.1 Reference Analysis Deviation Table (Attachment 1B)
Discussion of time constraints identified in Attachment 1A table.
Items 1-3: For floods, plant shutdown begins when river level reaches 558', and it is predicted to exceed elevation 565, per Abnormal Operating Instruction, 0-AOI-100-3 (Ref 1b). This is more than 5 days before flood waters would reach plant grade level (565', based on UFSAR Section 2.4 Ref. 3a). Deployment of Flexible and Diverse Coping Mitigation Strategies (FLEX) Pumping Systems must be complete before flood waters reach the transport path, which shall be at plant grade or higher.
FLEX pumps have been estimated to be deployed within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> by walkthrough, 480v Flex DG has been estimated to be deployed within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> by tabletop demonstration and 4kv Flex Support DG have been estimated to be deployed within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> (to be confirmed during the design/staffing evaluation process). A Design Basis Flood (DBF) would not reach the maximum flood height (elevation 572) for which Emergency Core Cooling System (ECCS) equipment is qualified for at least another 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> based on the Updated Final Safety Analysis Report (UFSAR) estimate above (Ref. 3a). Start-up of the 4 kV FLEX Support DGs and 480 V FLEX Generators can be performed after the normal emergency generators are lost.
Item 4: DBF level is reached. (Peak elevation and timing based on UFSAR Section 2.4, Figure 16 (Ref. 3ai)).
Item 5: Phase 1 commences when ELAP & loss of the UHS occur. All 3 units are assumed to have been operating at 100 percent rated thermal power for at least 100 days or have just been shut down from such a power history as required by plant procedures in advance of the impending event. For floods, FLEX deployment would have already been complete and the units would be at cold shutdown.
Item 6: Normal plant response to loss of offsite power.
Item 7: Normal plant response to loss of offsite and onsite AC power (Station Blackout, SBO)
Item 8: RPV depressurization starts at 20 minutes at a rate up to 100°F/hr in accordance with site procedures.
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Reactor Pressure Vessel (RPV) controlled depressurization will be governed by new BWROG Emergency Procedure Guideline (EPG) guidance (Ref. 5 and 7).
Based on the modeling in the evaluation, plant systems were demonstrated to support requirements for core cooling, and containment integrity. Since Operators will still be in the design basis SBO procedures, the SBO procedures must also stipulate this depressurization until the conditions for exiting the design basis SBO procedures are met. Main Steam Relief Valve (MSRV) control is maintained from the control room with sufficient DC power and pneumatic pressure to operate the MSRVs throughout Phase 1 and Phase 2 (if required). According to GEH studies (Ref. 7), the MSRV pilot solenoid coil electrical resistance will increase due to a higher containment temperature with a longer duration event than an existing SBO coping time. Browns Ferry Nuclear Plant will evaluate MSRV qualification against the predicted containment response with FLEX implementation to ensure there will be sufficient DC bus voltage during the Extended Loss of AC Power (ELAP) event (Open Item, OI 4). If required, there will be a modification to increase voltage as necessary to achieve the necessary coil current, or modifications will be made to reduce the coil resistance under higher temperature conditions. Because the MSRV control system will be exhausting control gas to the containment and containment pressure will be higher, BFNP is evaluating methods to establish any required increases in pneumatic supply pressure and modifications that may be required to ensure a supply of control gas for the MSRVs over the longer ELAP interval.
Item 9: Dispatch personnel to start deployment of the applicable Diesel Driven FLEX Pumping Systems. (Note: these pumps will have already been deployed for a DBF (see Item 2). Direction to deploy the FLEX Pumping Systems will be contained in site procedures.
Item 10: Dispatch personnel to start deployment of the 480v FLEX DG. (Note: the 480v FLEX DG will have already been deployed for a flood event (see Item 2). Direction to deploy the 480v FLEX Generators will be contained in site procedures.
Item 11: < 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />, Entry into ELAP - Time critical at a time greater than 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />.
A period of one hour is selected conservatively to ensure that ELAP entry conditions can be verified by control room staff and it is validated that Emergency Diesel Generators (EDGs) are not available. One hour is a reasonable assumption for Operators to perform initial evaluation of the EDGs. Entry into ELAP provides guidance to Operators to perform ELAP actions. A formal validation of the timeline will be performed once the procedure guidance is developed and related staffing study is completed (Open Item, OI 15, 16).
Cooldown is continued to a final pressure of approximately 150 psig to 250 psig (Cooldown will be complete for flood events)
Item 12: New procedure guidance is to be developed as part of the FSGs. Initial load shedding must be complete by T+4 to extend battery capability to 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> (Ref. 2).
A table top evaluation was performed by site personnel to obtain a one hour estimate, leaving a margin of one hour (before T+4). A formal validation of the timeline will be performed once the procedure guidance is developed and related staffing study is completed (Open Item, OI 15, 16). The breakers to be operated are Page 11 of 96
in the control bay in normally accessible areas and will be marked for ready identification during ELAP conditions.
The locations to implement shallow load shed are in the following rooms:
x Control Bay - Battery Board Rm 1 - El 593',
x Control Bay - Battery Board Rm 2 - El 593',
x Control Bay - Battery Board Rm 3 - El 593',
x Control Bay - 250 V DC Reactor MOV Board 1A - El 621',
x Control Bay - 250 V DC Reactor MOV Board 2A - El 621',
x Control Bay - 250 V DC Reactor MOV Board 3A - El 621',
x Control Bay - 250 V DC Reactor MOV Board 1B - El 593 ,
x Control Bay - 250 V DC Reactor MOV Board 2B - El 593'.
Item 13: At T+>2 hours - At the expected cooldown rate the RPV is being maintained above 150 psig.
Item 14: At T+<4 hours - Initial DC load shedding is complete.
Item 15: Use of the Torus vent would only be in accordance with Generic Letter 89-16 (preliminary MAAP analysis under evaluation); due to rescinding of NRC Order EA-12-050 and issuance of NRC Order 13-109. The currently installed hardened Torus vent is only designed to vent a single reactor unit and any changes to the system will be driven and in compliance with NRC Order EA-13-109. TVA will transmit a request for relaxation of full compliance with NRC Order EA-12-049 until a severe accident capable vent is installed in accordance with NRC Orde EA13-109. The hardened wetwell vent was installed in accordance with Generic Letter 89-16, Installation of a Hardened Wetwell Vent. BFN will rely on the existing Torus venting capabilities in the interim.
Item 16: 480v FLEX generator is deployed and connected to the safety related battery charger for each unit. Battery charging commences.
Item 17: A tabletop and pump demonstration indicates this can be complete in 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />, beginning with the SBO. Crews have done an exercise to install and pump with the low pressure FLEX pumps; however, the augmented suction lift for extreme low lake level has not yet been practiced. Further evaluations and improvements will be pursued and it is anticipated that the deployment time can be reduced to 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.
Formal validation of the timeline will be performed once procedural guidance is developed and the related staffing study is complete.
Item 18: EECW aligned to RCIC oil cooler (requires modification) before temperature is in far excess of 240 degrees F. EECW is supplied by FPS1.
Item 19: With access to the Ultimate Heat Sink (UHS) established via FLEX low pressure diesel driven pumps, the reactor depressurization may be commenced. This will be a decision point contained within new procedures; that will allow the Shift Manager
/ Site Emergency Director to evaluate reliability of the RCIC system and direct injection with the FLEX Pumping Systems as deemed appropriate.
Page 12 of 96
Item 20: 4kv FLEX Support Generators are deployed and connected. The 4kv safety related distribution system is available for service.
Item 21: Sustained coping will be supported by maintaining FLEX equipment fuel and in service.
Item 22: Add water to the SFP from the river using FLEX Pumping System, FPS1 through either the connection to the condensate storage and supply system or through the EECW supply line for emergency SFP makeup.. This will be done if it is not possible to establish makeup from FPS2 or FPS3 via the RHR supplemental fuel pool cooling / makeup lineup.
This is done if necessary to maintain the fuel in the pool submerged sufficiently to prevent damage and to provide adequate shielding. The SFP need not be maintained at normal water level and additional FLEX guidance will be developed using the systems from Order EA 12-051 (Ref. 11) (Open Item, OI 12). If the evaporation rate from the SFP is very high, it will be because the unit has just returned to service from a refueling outage.
Item 23: The industry will establish two Regional Response Centers (RRC) in order to support utilities during beyond-design-basis events. Flex equipment will be stored at staging are B. Fuel support for FLEX equipment will be provided after the first 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> in accordance with the TVA playbook (the Regional Response Centers plan for coordinating with each utility). TVA will have enough diesel fuel onsite for the first 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> (Open Item, OI 3).
Item 24: Sargent and Lundy Study: Loss of HVAC During ELAP (Ref. 12) specifies manual actions to ensure acceptable hydrogen limits in the battery rooms. A formal validation of the timeline will be performed once the procedure guidance is developed and related staffing study is complete (Open Item, OI 15, 16).
Item 25: Sargent and Lundy Study: Loss of HVAC During ELAP (Ref. 12) specifies manual actions needed to ensure acceptable room temperatures. A formal validation of the timeline will be performed once the procedure guidance is developed and related staffing study is complete (Open Item, OI 15, 16).
Technical Basis Support information
- 1. On behalf of the Boiling Water Reactor Owners Group (BWROG), GEH Evaluation of FLEX Implementation Guidelines, NEDC-33771P, Revision 0 (Ref. 7) to supplement the guidance in NEI 12-06 (Ref. 9) by providing additional Boiling Water Reactor (BWR)-
specific information regarding the individual plant response to the ELAP and Loss of Ultimate Heat Sink (LUHS) events. The document includes identification of the generic event scenario and expected plant response, the associated analytical bases and recommended actions for performance of a site-specific gap analysis.
GEH Evaluation (Ref. 7) utilized the NRC accepted SUPERHEX (SHEX) computer code methodology for BWRs long term containment analysis for the ELAP analysis. As part of this document, a generic BWR 4/Mark I containment NSSS evaluation was performed.
TVA utilized this generic evaluation as appropriate to develop coping strategies.
Page 13 of 96
- 2. Environmental conditions within the station areas were evaluated utilizing Thermal Model Generator Methods (TMG).
- 3. Per the guidance in 10 CFR 50.63 and Regulatory Guide 1.155 BFNP is an alternate AC, four hour coping plant for Station Blackout (SBO) considerations. Applicable portions of supporting analysis have been used in ELAP evaluations as starting points for the evaluations performed to meet the guidance from NEI 12-06 (Ref. 9).
(Section 4) Provide a sequence of events and identify any time constraint required for success including the technical basis for the time constraint.
Ref: NEI 12-06, section 3.2.1.7 JLD-ISG-2012-01, section 2.1
References:
- 1. Abnormal Operating Instructions (AOIs)
- a. 0-AOI-100-3, Flood Above Elevation 558'
- 2. AREVA Engineering Information Record Document No.: 51-9198045-000, Browns Ferry Post Fukushima FLEX Response Evaluation
- 3. Browns Ferry Nuclear Plant (BFNP) Updated Final Safety Analysis Report (UFSAR)
Revision 31, 11/12
- a. Section 2.4A
- i. Figure 16 (Amendment 25)
- b. Section 14.6
- i. Figure 11 (Amendment 16)
- 4. BFNP Emergency Operating Instruction (EOI) Program Manuals
- 5. BWR Owners Group - Emergency Procedure and Severe Accident Guidelines, Revision 3 (February 2013)
- 6. Emergency Operating Instructions (EOIs)
- a. EOI-1 (Units 1, 2, and 3)
- b. EOI-2 (Units 1, 2, and 3)
- c. EOI-3 (Units 1, 2, and 3)
- 7. GEH Evaluation of FLEX Implementation Guidelines, NEDC-33771P, Revision 0
BFN-SBO-CASE-0003B-01-014-RHRHX 02222013
- 10. NUMARC 87-00, Guidelines and Technical Bases for NUMARC Initiatives Addressing Station Blackout at Light Water Reactors, Revision 1
- 11. Order to Enhance Spent Fuel Pool Instrumentation, EA-12-051
- 13. Surveillance Instructions
- a. 1-SR-3.4.9.1(1) Reactor Heatup and Cooldown Rate Monitoring
- 14. 1,2,3-AOI-78-1, Fuel Pool Cleanup System Failure Page 14 of 96
Notes:
None (Section 5) Identify how Describe how the strategies will be deployed in all modes.
strategies will be deployed in all modes.
Ref: NEI 12-06, section 13.1.6 Deployment routes shown in Figure 3b, Attachment 3 will be utilized to transport FLEX equipment to the deployment areas. The identified paths and deployment areas will be accessible during all modes of operation (however, deployment location for some equipment will be different for flood conditions and the identified paths may be inundated after deployment, in case of a beyond-design-basis flood). This deployment strategy will be included within an administrative program in order to keep pathways clear or to clear the pathways.
Debris removal guidance will be provided in the new procedure 0-FSI-6A, Beyond Design Basis External Event (BDBEE) Damage Assessment (Ref. 3) (Open Items, OI 2 and OI 14).
References:
- 1. Attachment 3
- a. Figure 4
- 3. 0-FSI-6A, Beyond Design basis External Event (BDBEE) Damage Assessment Notes:
None Page 15 of 96
(Section 6) Provide a milestone The dates specifically required by the order are obligated schedule. This schedule should or committed dates. Other dates are planned dates subject include: to change. Updates will be provided in the periodic (six x Modifications timeline month) status reports.
o Phase 1 Modifications See attached milestone schedule Attachment 2 o Phase 2 Modifications o Phase 3 Modifications x Procedure guidance development complete o Strategies o Maintenance x Storage plan (reasonable protection) x Staffing analysis completion x FLEX equipment acquisition timeline x Training completion for the strategies x Regional Response Centers operational Ref: NEI 12-06, section 13.1 See attached milestone schedule in Attachment 2.
References:
- 1. Attachment 2
None Page 16 of 96
(Section 7) Identify how the Provide a description of the programmatic controls programmatic controls will be equipment protection, storage and deployment and met. equipment quality. See section 11 in NEI 12-06. Storage of equipment, 11.3, will be documented in later sections of this Ref: NEI 12-06 section 11 template and need not be included in this section.
JLD-ISG-2012-01 section 6.0 See section 6.0 of JLD-ISG-2012-01.
Browns Ferry Nuclear Plant will implement an administrative program for implementation and maintenance of the BFNP FLEX strategies in accordance with NEI 12-06 guidance.
x Equipment quality: The equipment for ELAP will be dedicated to FLEX and will have unique identification numbers. Installed structures, systems and components pursuant to 10 CFR 50.63(a) (Ref. 1) will continue to meet the augmented quality guidelines of Regulatory Guide 1.155, Station Blackout (Ref. 4).
x Equipment protection: BFNP will construct structures to provide protection of the FLEX equipment to meet the requirements identified in NEI 12-06 section 11 (Ref. 3a).
The schedule to construct the structures is still to be determined.
x Storage and deployment: BFNP will develop procedures and programs to address storage structure requirements and deployment/haul path requirements relative to the hazards applicable to BFNP.
x Maintenance and Testing: BFNP will utilize the standard EPRI industry PM process for establishing the maintenance and testing actions for FLEX components. The administrative program will include maintenance guidance, testing procedures and frequencies established based on type of equipment and considerations made within the EPRI guidelines.
x Design Control: BFNP will follow the current programmatic control structure for existing processes such as design and procedure configuration.
References:
- 2. Draft Interim Staff Guidance JLD-ISG-2012-01, Compliance with Order EA-12-049, Order Modifying Licenses with Regard to Requirements for Mitigating Strategies for Beyond-Design-Basis External Events; Docket ID NRC-2012-0068
- a. Section 11
- 4. Regulatory Guide 1.155, Station Blackout
- 5. NPG-SPP-09.3, Plant Modifications and Engineering Change Control Notes:
None Page 17 of 96
(Section 8) Describe training List training plans for affected organizations or describe plan the plan for training development New training of general station staff and EP will be performed prior to the first BFNP unit design implementation outage. These programs and controls will be implemented in accordance with the Systematic Approach to Training (Open Item, OI 18).
References:
None Notes:
None (Section 9) Describe Regional Discussion in this section may include the following Response Center plan information and will be further developed as the Regional Response Center development is completed.
x Site-specific RRC plan x Identification of the primary and secondary RRC sites x Identification of any alternate equipment sites (i.e.,
another nearby site with compatible equipment that can be deployed) x Describe how delivery to the site is acceptable x Describe how all requirements in NEI 12-06 are identified The nuclear industry will establish two Regional Response Centers (RRCs) to support utilities during beyond-design-basis events. Each RRC will hold five sets of equipment, four of which will be able to be fully deployed when requested; the fifth set will have equipment in a maintenance cycle. Equipment will be moved from an RRC to a local Assembly Area, established by the Strategic Alliance for FLEX Emergency Response (SAFER) team and TVA.
Communications will be established between BFNP and the SAFER team and required equipment moved to the site as needed. First arriving equipment, as established during development of BFNPs playbook, will be delivered to the site within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> from the initial request.
TVA has established a contract with the SAFER team in accordance with the requirements of NEI 12-06, Section 12 (Open Item, OI 19).
References:
- 1. AREVA NP Inc., Engineering Information Record, Document No.: 51 - 9213690 - 001, SAFER Response Plan Master Templates Notes:
Page 18 of 96
None Maintain Core Cooling (Section 10) Determine Baseline coping capability with installed coping1 modifications not including FLEX modifications, utilizing methods described in Table 3-1 of NEI 12-06:
x RCIC/HPCI/IC x Depressurize RPV for injection with portable injection source x Sustained water source BWR Installed Equipment Phase 1:
Provide a general description of the coping strategies using installed equipment including modifications that are proposed to maintain core cooling. Identify methods (RCIC/HPCI/IC) and strategy (ies) utilized to achieve this coping time.
Power Operation, Startup, and Hot Shutdown At the initiation of the Beyond-Design-Basis External Event (BDBEE), Main Steam Isolation Valves (MSIVs) automatically close, feedwater is lost, and Safety Relief Valves (SRVs) automatically cycle to control pressure, causing reactor water level to decrease. When reactor water level reaches -45 inches from instrument zero, Reactor Core Isolation Cooling (RCIC),
1,2,3-OI-71 (Ref. 6a) and High Pressure Coolant Injection (HPCI), 1,2,3-OI-73 (Ref. 6b),
automatically start with normal suction from the Condensate Storage Tanks (CST) and inject to the RPV. This HPCI/RCIC injection recovers the reactor level to the normal band. Condensate Storage Tanks (CSTs) at BFNP are not qualified for all the hazards listed in Section 1 and therefore, are not credited for Phase 1 coping, but they would be used if available. The SRVs control reactor pressure, 0-AOI-57-1A, Loss of Offsite Power (161 and 500 KV)/Station Blackout (Ref. 1a). If a CST is NOT lost, it will be used for injection, after the safety related battery chargers are reenergized, and the heatup curve of the suppression pool will be less severe. If CST suction is available, this ultimately results in an increase in water mass in the suppression pool. Reactor Core Isolation Cooling (RCIC) will be used for vessel level control and Main Steam Relief Valves (MSRVs) will be used for pressure control. After 20 minutes, a cooldown is initiated near the maximum allowable rate (100°F/hour), per the guidance given in GEH Evaluation of FLEX Implementation Guidelines (Ref. 5) and AOI-57-1A.
After confirmation the Emergency Diesel Generators (EDGs) cannot be restarted, but no later than one hour, the crew enters the FLEX guidelines.
RCIC trip and isolation signals will be overridden in accordance with FLEX procedural guidance for ELAP. EOI Appendices will be utilized. Some already exist, others will be added by EPG Rev. 3. EOI Appendix 16A, Bypassing RCIC Low RPV Pressure Isolation - Lifted leads in el. 621 of the Reactor bldg. EOI Appendix 16H, Bypassing RCIC High RPV Water Level Shutdown Interlocks - Using Emergency transfer switch at breaker compartment, by verifying valve 71-8, Steam supply valve is open and placing switch in emergency. This is 1
Coping modifications consist of modifications installed to increase initial coping time, i.e., generators to preserve vital instruments or increase operating time on battery powered equipment.
Page 19 of 96
performed at 250 RMOV Bd 1C, 2C or 3C el. 565 of Reactor bldg. EOI Appendix 16K, Bypassing RCIC High Temperature Isolation - Booted contacts in Aux Instrument Room and El. 621 of the Reactor Bldg.
The automatic depressurization system will be prevented from automatically initiating while low pressure makeup is not available (with keylock switches). The primary method of reactor pressure control is operation of the MSRVs. Operator control of reactor pressure using MSRVs requires DC control power and pneumatic pressure (supplied by station batteries and the drywell pneumatics system, respectively).
When it is determined that the safety related battery chargers are not energized, personnel will be dispatched to perform DC load shed in order to increase availability of the batteries to at least 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />. New procedure, O-FSI-3G Load Shed of 250v Main Bank Battery 1, 2 & 3, is being developed to implement the load shed.
For Phase 1, power for the MSRVs is supplied by the station batteries. At event initiation the nitrogen storage tank, with a backup supply from the Containment Atmosphere Dilution system, automatically supplies pneumatic pressure for MSRV operation. However, these nitrogen tanks are not designed to withstand all BDBEE and a modification will be performed to provide a backup nitrogen control station within the Reactor Buildings for BFNP-1, 2 and 3. In addition, each Automatic Depressurization System (ADS) MSRV is provided an accumulator which contains enough pneumatic pressure to operate each valve through five open/close cycles, per the Updated Final Safety Analysis Report (UFSAR) (Ref. 3a). Mechanical SRV operation will also control reactor pressure at the safety relief setpoint.
RCIC exhaust and MSRV cycling will increase torus and drywell temperatures and pressures.
Plant stability can be maintained during Phase 1 of the beyond-design-basis event by following the guidance in GEH Evaluation of FLEX Implementation Guidelines (Ref. 5).
- 1. Containment design limits will not be exceeded for temperatures or pressures (Ref. 5).
- 2. Suppression pool temperature increases will not result in RCIC failure from lube oil heating or from loss of Net Positive Suction Head (NPSH) (considering the projected torus pressure) Browns Ferry Post Fukushima FLEX Response Evaluation (Ref. 2) and GEH Evaluation of FLEX Implementation Guidelines (Ref. 5). Browns Ferry Nuclear Plant will take actions as necessary to assure RCIC can operate at elevated temperatures (Open Item, OI 7).
- 3. Battery supplies will be sufficient for RCIC, Main Steam Relief Valves (MSRVs),
Hardened Containment Vent System (HCVS) and for indication, considering load shed manual actions, Browns Ferry Post Fukushima FLEX Response Evaluation (Ref. 2).
- 4. MSRV solenoid voltage will be sufficient for higher drywell temperatures up to 340 degrees F.
- 5. MSRV operating gas will be sufficient for higher drywell pressures.
In accordance with Emergency Procedure Guidelines (EPGs) and per Boiling Water Reactors Owners Group (BWROG) guidance, Emergency Operating Procedures (EOPs) have been revised to allow termination of RPV emergency depressurization at a controlled pressure reduction rate to a pressure that will allow continued RCIC operation, because steam driven RCIC is the sole means of core cooling (approximately 150-250 psig).
The Operators will use CST suction initially if it is available, and while this improves NPSH for RCIC and decreases the containment temperature trends, it can challenge Heat Capacity Page 20 of 96
Temperature Limit (HCTL) (for Torus/Suppression Pool), Pressure Suppression Pressure (PSP)
(a function of Primary Containment Water Level) or MSRV tailpipe limits because of the increasing water level in the torus. Without venting, the drywell design temperature limit of 281°F will be reached in approximately 9 hours1.041667e-4 days <br />0.0025 hours <br />1.488095e-5 weeks <br />3.4245e-6 months <br /> if suction is from the suppression pool. GEH Evaluation of FLEX Implementation Guidelines (Ref. 5) indicates the temperature limit will be reached at approximately 11 hours1.273148e-4 days <br />0.00306 hours <br />1.818783e-5 weeks <br />4.1855e-6 months <br /> if suction is from the CST. Emergency Operating Instructions (EOIs)/Flex Support Guidelines (FSGs) will be revised to direct Operators to terminate RPV emergency depressurization to prevent loss of RCIC.
By the end of 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />, the RCIC makeup rate required is approximately 240 gpm. If the CST is being used (and it is not credited), suction will be transferred either when suppression pool water level approaches the EOI limit (19 feet) or when the suppression pool temperature rises to a value that could threaten RCIC operation (~240 degrees by analysis contained in Project Task Report, BWROG RCIC Pump and Turbine Durability Evaluation - Pinch Point Study, 0000-0155-1545-R0 (Ref. 12)). Once suction is transferred to the suppression pool (which may be at the beginning of the event if the CST is lost due to the beyond-design-basis initiating event) essentially all of the mass added via RCIC injection into the reactor vessel is returned to the suppression pool by the MSRVs.
Cold Shutdown and Refueling The overall strategy for core cooling for Cold Shutdown and Refueling are, in general, similar to those for Power Operation, Startup, and Hot Shutdown.
If an ELAP occurs during Cold Shutdown, water in the vessel will heatup. When temperature reaches 212°F, (Hot Shutdown) the vessel will begin to pressurize. During the pressure rise RCIC can be returned to service with suction from the CST to provide injection flow. When pressure rises to the SRV setpoints then pressure will be controlled by SRVs. The primary and alternate strategies for Cold Shutdown are the same as those for Power Operation, Startup, and Hot Shutdown as discussed above for core cooling. The drywell airlock may be open, but the amount of steaming will have limited impact on the Reactor Building until Phase 2 manpower is available to shut the airlock before Phase 2 actions are required in the Reactor Building airlock area.
During Refueling, there are many variables that impact the ability to cool the core. In the event of an ELAP during Refueling, there are no installed plant systems available to cool the core; thus, transition to Phase 2 will occur immediately. Phase 2 is discussed in Section 11.
BFN will follow the guidance contained within the Nuclear Energy Institute (NEI) position paper dated September 18, 2013, entitled Position Paper: Shutdown/ Refueling Modes (Agencywide Documents Access and Management Systems (ADAMS) Accession No. ML13273A514) which the NRC has endorsed.
Page 21 of 96
Details:
(Section 10a) Confirm that procedure/guidance exists or will be developed to support Provide a brief implementation description of Procedures /
Strategies /
Guidelines Browns Ferry Nuclear Plant will utilize the industry developed guidance from the Owners Groups, EPRI and NEI Task team to develop site specific procedures or guidelines to address the criteria in NEI 12-06 (Ref. 6). These procedures and/or guidelines will support the existing symptom based command and control strategies in the current EOIs (Open Item, OI 17).
Maintain Core Cooling (Section 10b) Identify List modifications modifications x Change power supply of containment instrumentation (drywell atmospheric temperature and suppression pool level) from the AC instrument bus to station battery to provide continuous power to critical instruments so that critical containment parameters can be monitored throughout the event. (Open Item, OI 9) x Change power supply of RPV level instrument (shutdown floodup range) to provide continuous power to allow an expanded level range to be monitored.
x Install a protected nitrogen control station to provide backup pneumatic supply to the MSRVs. (Open Item, OI 4) x Perform modifications, as necessary, to ensure that the RCIC inventory control function is seismically robust. (Open Item, OI 8) x Label non-critical DC loads to allow Operators to more readily identify the loads that will be shed during the Phase 1 load shedding activity. (Open Item, OI 9)
(Section 10c) Key Reactor List instrumentation credited for this coping evaluation.
Parameters 1,2,3-LI-3-52 Reactor Vessel Water Level - Post Accident Flood Range (Div I) 1,2,3-LI-3-62 RPV Level Reactor Vessel Water Level - Post Accident Flood Range (Div II) 1,2,3-LI-3-58A Reactor Vessel Water Level - Emergency Systems Range (Div I) 1,2,3-LI-3-58B Reactor Vessel Water Level - Emergency Systems Range (Div II) 1,2,3-PI-3-74A Reactor Pressure (Div I) 1,2,3-PI-3-74B Reactor Pressure (Div II) 1,2,3-LI-3-55 Shutdown Floodup Range Page 22 of 96
The instrumentation listed above is or will be supplied power via the Class 1 Safety Related Batteries and are located in the Main Control Room. A reference source for the plant operators will be developed that provides approaches to obtaining necessary instrument readings to support the implementation of the coping strategy (NE 12-06, Section 3.2.1.10). This reference source should include control room and non-control room readouts and should also provide guidance on how and where to measure key instrument readings as close to containment penetrations, as possible, where available. Portable instrument (e.g., a Fluke meter) can be used, as applicable. Such a resource could be provided as an attachment to the plant procedures/guidance. Guidance will include critical actions to perform until alternate indications can be connected and on how to control critical equipment without associated control power (Open Item, OI 5). Browns Ferry's evaluation of the FLEX strategy may identify additional parameters that are needed in order to support key actions identified in the plant procedures/guidance or to indicate imminent or actual core damage (NEI 12-06 Rev. 0 Section 3.2.1.10) and any differences will be provided in a future 6-month update following identification.
Maintain Core Cooling
References:
- 1. Abnormal Operating Instructions (AOIs)
- a. 0-AOI-57-1A, Loss of Offsite Power (161 and 500 KV)/Station Blackout
- 2. AREVA Engineering Information Record Document No.: 51-9198045-000, Browns Ferry Post Fukushima FLEX Response Evaluation
- 3. Browns Ferry Nuclear Plant (BFNP) Updated Final Safety Analysis Report (UFSAR)
- a. Section 4.4-4
- 5. GEH Evaluation of FLEX Implementation Guidelines, NEDC-33771P, Revision 0
- 7. Plant Operating Instructions
- a. 1-OI-71, RCIC System
- b. 1-OI-73, HPCI System
- 8. Position Paper: Shutdown/ Refueling Modes (Agencywide Documents Access and Management Systems (ADAMS) Accession No. ML13273A514)
- 10. Unit 1,2,3 Technical Requirements Manual Bases 3.3.3.1, Post Accident Monitoring (PAM) Instrumentation
- 11. O-FSI-3G Load Shed of Class 1E 250v DC Battery
- 12. Project Task Report, BWROG RCIC Pump and Turbine Durability Evaluation - Pinch Point Study, 0000-0155-1545-R0 Notes:
The duration of each station battery was calculated to last no less than 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> following a load shed at 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />.
Page 23 of 96
Maintain Core Cooling (Section 11) BWR Portable Equipment Phase 2:
Provide a general description of the coping strategies using on-site portable equipment including modifications that are proposed to maintain core cooling. Identify methods (RCIC/HPCI/IC) and strategy (ies) utilized to achieve this coping time.
During Phase 1, plant personnel deploy FLEX equipment. For flood events, the equipment is staged many hours before the peak flood waters exceed the design basis (see Attachment 1A).
For other events, equipment deployment is initiated beginning with the SBO condition - in some cases, before an ELAP is declared (see timeline, Attachment 1A).
The following is a list of major equipment that is planned to be onsite, protected (within the limitations described) and ready for use at or before the beginning of Phase 2.
- 1) Two redundant 850kw, 480v FLEX Generators will be permanently staged in the FESB to meet N+1 requirements. They are protected for all of the extreme natural events in Section
- 1. A single DG has sufficient capacity to supply all safety related 250v battery chargers via a load control center that will be used for distribution.. These will be available during Phase 2; by connection directly to the input supply breaker to the chargers (Refer to Attachment 3, Figure 1)
- 2) Two 1.1MWe, 4kv FLEX Support Generators will be permanently staged in the FESB. It is currently estimated that these generators can be deployed within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. They would be used to energized the safety related 4kv distribution system and energize loads such as 120v ac instrumentation, ventilation, pump motors and motor operated valves.
- 3) Each FLEX Pumping System (FPS1, FPS2, FPS3, FPS+1) consists of a portable FLEX Low Pressure Pump (FLPP) driven by a 600 HP diesel pump rated at 5000 gpm at 150 psi discharge head and a FLEX Floating Booster Pump (FLBP). The FLBP is an integrated, transportable pumping module capable of providing up to 5,000 gpm of water at 90 ft. total dynamic head. The system utilizes two floating submersible pumps, designated satellite pumps, to supply water from an open source to a remote high-capacity pumping system, located as high as 50 ft. above and 150 ft. away in distance. A 300 hp diesel engine powers the hydraulic system. Two engine mounted variable displacement pumps provide pressurized hydraulic fluid to the satellite pump motors through 150 ft. hose lines. The hose lines are retrieved and stored on two hose reels driven independently by electric motors. An electronic engine management system controls and monitors the engine and provides the operator with real time supervision of all critical engine parameters and hydraulic conditions (Refer to Attachment 3, Figure 5). TVA is designing deployment locations for the pumps, including ramps, winches or other transfer assemblies as necessary to deploy all pumps and hoses within the Phase 1 coping interval. The staff begins deployment of these pumps as soon as SBO occurs rather than waiting to exhaust all attempts to restore the emergency electric supply system. It is currently estimated that FPS1, FPS2 and FPS3 will be deployed and connected to provide backup RPV, SFP and Containment level addition at approximately 6, 7, and 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> respectively into the event. The staff begins deployment of Page 24 of 96
Maintain Core Cooling (Section 11) BWR Portable Equipment Phase 2:
these pumps as soon as SBO occurs rather than waiting to exhaust all attempts to restore the emergency electric supply system.
a) FLEX Pumping Systems are assigned as follows.
i) FPS1 can be connected to one or more of the following:
(1) Three Containment Integrated Leak Rate Test (CILRT) penetrations through Reactor Building wall, elevation 565' (4" pipe) - inside 1A, 2A, 3A RHRSW pipe tunnel, (From inside the Reactor Building, connections can be made to the Condensate Storage & Supply System and then to the vessel through RHR Loop I & II LPCI injection lines and Core Spray Loop I & II injection lines, to SFP makeup (normal), or to the Containment and Torus via their respective RHR Loop I and II flowpaths),
(2) The EECW South header - At the intake structure (The EDGs will be isolated by manual action if needed to ensure adequate cooling to operating SSCs). The south header can be used for SFP makeup and for all normally supplied loads with the exception of the control air compressors.
ii) FPS2 will be aligned to B RHRSW at the following location; (1) At the intake structure, Note: The B RHRSW can provide standby coolant to Unit 2 and/or Unit 3, if needed.
iii) FPS3 will be aligned at the following location:
(1) At the intake structure, Note : The D RHRSW can provide standby coolant to Unit 1 and/or Unit 2, if needed.
iv) (FPS4) - (N+1), is a spare.
- 4) Augmented operating gas will be staged for the Main Steam Relief Valves (MSRVs).
Primary Phase 2 strategy for a unit that is not in cold shutdown.
During Phase 2, as in Phase 1, reactor core cooling is initially maintained using RCIC in automatic or manual mode (i.e., with Operators controlling the RCIC flow controller) with suction from the suppression pool or the CST (if available). The CST is not credited as being able to sustain all events in Section 1; however, it would be used if available, because it provides additional margin before containment temperature is challenged, and it reduces the temperature of the RCIC bearing cooler. This plan addresses CST use because if the CST survives, its use requires consideration of the need for mass removal from the CST.
Reactor Core Isolation Cooling (RCIC) will ultimately be secured with vessel makeup taken over by FPS2 and/or FPS3. Suppression pool water level will increase if there is addition from the CST (if it is not offset by anticipatory venting of the wetwell). Addition of water from the CST will be terminated if necessary to prevent challenging the containment control limits and to maintain availability of the Hardened Containment Vent System (HCVS). The battery Page 25 of 96
Maintain Core Cooling (Section 11) BWR Portable Equipment Phase 2:
chargers will be available from either the 480 V FLEX DGs or Spare 480v FLEX DG..
Suppression pool water level can be reduced by operation of HPCI (after battery chargers are available) in modified CST test mode (suction from torus, discharge to the CST, if available).
Containment pressure could also potentially be used as a driving force to reject water from the torus back to the CST without pumping power (RHR drain pump system); however, this alternative is still under consideration. These strategies are still evaluation.
FPS2 and FPS 3 will use the Tennessee River as their source of suction supply. The pumps will be deployed in the vicinity of the Intake Pumping Station, depending on whether the event is a flood or non-flood event will determine the exact deployment location (Attachment 3, Figure 2A & 2B). Debris entering into the suction of FPS2 and FPS 3 will be mitigated by strainers located in the suction supply flowpath. The BWROG has issued BWROG-TP 006, Rev. 0 March 2014, Fukushima Response committee Raw Water Issue: Fuel inlet blockage from debris, to address fuel blockage from debris present in raw water injection. If the fuel inlet becomes blocked, assuring that injected water reaches the inside core shroud region and thus enter the fuel through the top of the channel is the primary strategy.
Utilization of this strategy requires approval and implementation of an expanded water level band (the upper band which would be just below the main steam lines) in the Emergency Operating Instructions that is being tracked by the BWROG Emergency Procedures Committee under issue 1216.
During Phase 2, reactor pressure is controlled by manual operation of MSRVs as described in Phase 1. As backup to the nitrogen tank and the MSRV accumulators, a pre-staged emergency N2 control station will be utilized, as necessary. This N2 control station will be added by plant modification.
Alternate Phase 2 strategy for a unit that is not in cold shutdown.
RCIC will continue to supply makeup to the reactor vessel as in Phase 1.
The discussion in this paragraph is applicable to Unit 2 only. During Phase 2, the HCVS will be opened for anticipatory venting; otherwise the drywell temperature limit would be reached per GEH Evaluation of FLEX Implementation Guidelines (Ref. 5). Hardened Containment Vent System (HCVS) operation will be controlled to ensure overpressure for RCIC NPSH. The mass loss through the HCVS (225 gpm estimated in Ref. 5) will eventually have to be made up. If Phase 3 is not available yet, the torus level will be restored as needed using FLEX Pumping System, FPS2 or FPS3 (water from the Tennessee River). Suppression pool and containment temperatures/pressures will eventually be reduced and RCIC operation can continue for vessel injection as long as the steam supply is adequate.
If Phase 3 has not been entered when RCIC goes offline, FLEX Pumping System, FPS2 and FPS3 can be used to provide vessel makeup after pressure is lowered (normally; however, if the Page 26 of 96
Maintain Core Cooling (Section 11) BWR Portable Equipment Phase 2:
decay heat is no longer sufficient to maintain a continuous RCIC steam supply, RCIC would be operated intermittently until a low pressure makeup from the cleanest water source available could be placed in service either in Phase 2 or 3). Alternatively, FLEX Pumping Systems (FPS2 or FPS3) can provide river water injection to the vessel via the standby coolant crosstie from RHRSW. Vessel makeup (T+6 hours and later) requirements will be less than 250 gpm (Ref. 5); therefore, use of FPS2 or FPS3 supplies will not significantly impact the other units that will be using this strategy.
Primary strategy for a unit that is less than RCIC supply pressure at the time of the external event:
If the plant operates in Mode 3 when the SBO occurs, there is more time available to align and start the FLEX Pumping Systems than is the case for Mode 4 operation, Technical Justification to Support Risk Informed Modification to Selected Required Action End States for BWR Plants (Ref. 4). The reason more time is available in Mode 3, which increases the probability of success, is availability of RCIC. The strategy is to transition from Mode 4 to Mode 3 with minimal inventory loss. When RCIC is started, the makeup rate is greater than the mass loss from the core. With no inventory loss other than normal system leakage (TS limit), there is sufficient water to prevent uncovering the core before the FLEX Pumping Systems can be utilized in Phase 2.
Primary strategy for a unit that is in Cold Shutdown and Refueling:
During Refueling, many variables exist which impact the ability to cool the core. In the event of an ELAP during Refueling, there are no installed plant systems available to cool the core; thus, transition to Phase 2 will occur immediately. To accommodate the activities of vessel disassembly and refueling, water levels in the reactor vessel and the reactor cavity are often changed. The most limiting condition is the case in which the reactor head is removed and water level in the vessel is at or below the reactor vessel flange. If an ELAP/LUHS (Extended Loss of AC Power /Loss of Ultimate Heat Sink) occurs during this condition then boiling in the core may occur quite rapidly (dependent on the time after shutdown).
Pre-staging of FLEX pumps, except in case of events with adequate warning times, cannot be credited per the guideline of NEI 12-06 (Ref. 6) since an event could disable any pre-staged pump. Deploying and implementation of FLEX equipment to supply injection flow must commence immediately from the time of the event and must be rapid enough to prevent fuel uncovery. Note that the rate of heat addition in cold shutdown is low and the required vessel makeup rate is very low; therefore, there should be sufficient time to establish vessel injection.
During an outage period, there are more personnel on site to provide the necessary resources.
Guidance will be provided to ensure that sufficient area is available for deployment and that haul paths remain accessible without interference from outage equipment during refueling outages. Outage risk management procedures will be updated to include FLEX equipment as part of outage risk management.
Page 27 of 96
Maintain Core Cooling (Section 11) BWR Portable Equipment Phase 2:
BFN will follow the guidance contained within the Nuclear Energy Institute (NEI) position paper dated September 18, 2013, entitled Position Paper: Shutdown/ Refueling Modes (Agencywide Documents Access and Management Systems (ADAMS) Accession No. ML13273A514) which the NRC has endorsed.
Details:
(Section 11a) Confirm that procedure/guidance exists or will be developed to support Provide a brief implementation
description of Procedures /
Strategies /
Guidelines Browns Ferry Nuclear Plant will utilize the industry developed guidance from the Owners Groups, EPRI and NEI Task team to develop site specific procedures or guidelines to address the criteria in NEI 12-06 (Ref. 6). These procedures and/or guidelines will support the existing symptom based command and control strategies in the current EOIs (Open Item, OI 17).
Maintain Core Cooling (Section 11) BWR Portable Equipment Phase 2:
(Section 11b) Identify List modifications all connections will be accessible modifications x Construct a Flexible Equipment Storage Building (FESB), located above the Probable Maximum Flood (PMF) level, which is adequately protected from the hazards listed in Section 1. The storage facility(s) will be used to store support equipment and items, including the four FLEX Pumping Systems, one Spare FLEX DG, equipment deployment vehicles and debris/snow clearing equipment. (Open Items, OI 9 and OI 10) x Provide adequate staging area above the PMF for the 480v generators and connection points to provide power to the class 1E safety related battery chargers. Provide a load distribution center to supply other auxiliary power requirements.
x Install connection points on the B and D RHRSW piping at the Intake for the FLEX pump discharge hose connections. B header provides Unit 2 & Unit 3 compliance.
D header provides Unit 1 & Unit 2 compliance.
Page 28 of 96
x Install connection point(s) on the common South EECW header piping at the Intake Structure for the FLEX pump discharge hose connections (common system for all 3 units).
x Modify currently installed hardened wetwell vent to install backup pneumatic supply or provided procedural guidance for manual operation, to allow use within current design limits. (Open Items, OI 9 and OI 11) x Modify RCIC lube oil cooling line to allow a hose to be connected from the South EECW header nearby to provide turbine lube oil cooling for RCIC. This strategy utilizes FPS1 to provide the cooling water supply.
(Section 11c) Key List instrumentation credited or recovered for this coping evaluation.
Reactor Parameters Same as instruments listed in above section, Maintain Core Cooling Phase 1 (Section 11d) Storage I Protection of Equipment :
Describe storage / protection plan or schedule to determine storage requirements Seismic List how equipment is protected or scheduled to protect Portable equipment and connection materials required to implement this FLEX strategy will be maintained in the FESB or another structure, which is designed to meet or exceed BFNP design basis Safe Shutdown Earthquake (SSE) protection requirements.
Flooding List how equipment is protected or scheduled to protect Note: if stored below current flood level, then ensure procedures exist to move equipment prior to exceeding flood level Portable equipment required to implement this FLEX strategy will be maintained in the FESB, which is sited in a suitable location that is above the PMF level and as such is not susceptible to flooding from any source. FLEX equipment deployment paths maintain a minimum elevation of 565' for which the plant will have over 5 days to deploy FLEX equipment based on plant response to a flooding event in 0-AOI-100-3 (Ref. 1b). See Updated Final Safety Analysis Report (UFSAR) Section 2.4A, Figure 16 (Ref. 3a)
Severe Storms with List how equipment is protected or scheduled to protect High Winds Portable equipment required to implement this FLEX strategy will be maintained in the FESB which is designed to meet or exceed the licensing basis high wind hazard for BFNP.
Snow, Ice, and List how equipment is protected or scheduled to protect Extreme Cold The FESB will be evaluated for snow, ice, and extreme cold temperature effects. Heating will be provided as required to assure no adverse effects on the FLEX equipment. The FESB will Page 29 of 96
have a stand-alone HVAC system.
High Temperatures List how equipment is protected or scheduled to protect The FESB will be evaluated for high temperature effects and ventilation will be provided as required to assure no adverse effects on the FLEX equipment. The FESB will have a stand-alone HVAC system.
(Section 11e) Deployment Conceptual Modification (Attachment 3 contains Conceptual Sketches)
Strategy Modifications Protection of connections Identify strategy including Identify modifications Identify how the connection how the equipment will be is protected deployed to the point of use.
x Three FLEX Pumping Systems will be deployed to supply river water into existing systems.
x FLEX Pumping x Install hose connections System (FPS1) will be sized for FPS1 on the deployed to supply EECW header that will be water into the South connected to the South EECW header via EECW header at the intake installed connections pumping station.
at the intake pumping station.
x FLEX Pumping x Install hose connections The connections are being System (FPS2) will be sized for FPS2 on the installed on piping that are in deployed to supply RHRSW B header at the a seismically designed water into the intake pumping station. structure and are not RHRSW B header B header provides Unit impacted by outside hazards.
via installed 2 & Unit 3 compliance.
connections at the D header provides Unit intake pumping 1 & Unit 2 compliance.
station.
x FLEX Pumping x Install hose connections Connection points will be System (FPS3) will be sized for FPS3 on the made within the Seismic deployed to supply RHRSW D header at the Class 1 Control Bay.
water into the intake pumping station.
RHRSW D header via installed connections at the intake pumping Page 30 of 96
station.
x 480v FLEX DG for x Modify staging area to Emergency Diesel generator battery charging and facilitate PMF, provide 7-day tanks are located other loads connections to the class 1E underneath the safety related safety related battery Diesel Generators and chargers and provide a load protected from all the distribution center. conditions listed in NEI 12-06, Section 1. The deployment trucks and portable fuel transfer pumps will be stored in the FESB which is protected from all the conditions listed in NEI 12-06, Section 1.
x Portable fuel transfer x Modifications may be pumps will remove fuel performed to facilitate from the Emergency access to the Emergency Diesel Generator 7 day Diesel Generator 7 day tanks to fill equipment tanks and facilitate portable fuel tanks. Deployment fuel transport pump trucks will also be connection.
equipped with a fuel storage tank to transfer fuel to locations in need of fuel.
x Expand the upper band of x Provide DC power supply Instrument and power supply RPV level that should be to 1,2,3-LI-3-55, Shutdown are located in seismic class 1 maintained when raw Floodup Range, in order to structure water is injected to the monitor an expanded water RPV. level band up to the bottom of the Main Steam Lines (to ensure adequate core cooling with inlet core debris clogging)
References:
- 1. Abnormal Operating Instructions (AOIs)
- a. 0-AOI-57-1A, section 4.2
- b. 0-AOI-100-3, Flood Above Elevation 558'
- 2. Attachment 1A Timeline, Attachment 1A Page 31 of 96
- 3. Browns Ferry Nuclear Plant (BFNP) Updated Final Safety Analysis Report (UFSAR)
- a. Section 2.4A
- 4. BWROG Report, NEDC-32988-A, Rev 2, "Technical Justification to Support Risk Informed Modification to Selected Required Action End States for BWR Plants,"
Section I (NRC's SE) and Section II (Responses to NRC's RAI), ML030170060
- 5. GEH Evaluation of FLEX Implementation Guidelines, NEDC-33771P, Revision 0
- a. Section 7.3.1.1.b
- 7. BWROG-TP-14-006, Revision 0 March 2014, Fukushima Response Committee Raw Water Issue: Fuel inlet blockage from debris
- 8. BWROG Emergency Procedure Committee, Issue 1216 Notes:
None Maintain Core Cooling (Section 12) BWR Portable Equipment Phase 3:
Provide a general description of the coping strategies using Phase 3 equipment including modifications that are proposed to maintain core cooling. Identify methods (RCIC/HPCI/IC) and strategy(ies) utilized to achieve this coping time.
Primary (and Alternate) Strategy For Phase 3, the core cooling maintenance strategy is initially dependent on the strategy being implemented in Phase 2 (primary or alternate); however, the end state strategy is the same.
- 1. Phase 3 will provide additional support to continue and reinforce the Phase 2 strategy.
Phase 3 will provide (6) ~ 1 MWe Generators & load distribution centers, high capacity low pressure pumps with booster pump assemblies to backup FPS1, FPS2, & FPS3, additional diesel fuel, supplies and redundancy for the FLEX equipment being used. Additionally, Phase 3 equipment capable of providing for demineralized water to makeup to the torus, Spent Fuel Pool (SFP), and Reactor Pressure Vessel (RPV) as necessary.
Details:
(Section 12a) Confirm that procedure/guidance exists or will be developed to support Provide a brief implementation description of Procedures /
Strategies /
Guidelines Page 32 of 96
Maintain Core Cooling (Section 12) BWR Portable Equipment Phase 3:
Browns Ferry Nuclear Plant will utilize the industry developed guidance from the Owners Groups, EPRI and NEI Task team to develop site specific procedures or guidelines to address the criteria in NEI 12-06 (Ref. 1). These procedures and/or guidelines will support the existing symptom based command and control strategies in the current EOIs (Open Item, OI 17).
Maintain Core Cooling (Section 12b) List modifications Identify modifications x The RRC pumps, if needed (to replace the FLEX Pumping Systems in service), will utilize the same piping connections developed for Phase 2.
x Modifications will allow for the connection of RRC DGs to replace any FLEX DG that has failed.
(Section 12c) Key Reactor List instrumentation credited or recovered for this coping Parameters evaluation.
Same as instruments listed in Section10c, augmented by the instruments associated with monitoring the DGs and Pumping Systems provided by the RRC.
(Section 12d) Deployment Conceptual Modification (Attachment 3 contains Conceptual Sketches)
Strategy Modifications Protection of connections Identify strategy including Identify modifications Identify how the connection is how the equipment will be protected deployed to the point of use.
Phase 3 equipment will be No modifications x The FLEX/RRC pump make-up provided by the RRC, identified for Phase 3 connections are the same as which is to be located in deployment issues described for Phase 2 and shall Memphis, TN. be protected against the specific Equipment transported to hazards used in the strategy (i.e.,
the site will be either some high point connections may immediately staged at the be isolated and not used for Page 33 of 96
point of use location tornadoes, but implemented for (pumps and generators) or floods).
temporarily stored at the x The 480 VAC FLEX connection lay down area shown on panels are located in a structure Figure 4 until moved to and at an elevaation protected for the point of use area. all hazards. The RRC 480 VAC Deployment paths DGs can be connected even if the identified on Figure 4 will 480 V FLEX Generators were be used to move lost in a tornado event.
equipment as necessary. x All other equipment will be portable.
Expand the upper band of Provide DC power supply Instrument and power supply are RPV level that should be to 1,2,3-LI-3-55, located in seismic class 1 structure maintained when raw Shutdown Floodup Range, water is injected to the in order to monitor an RPV. expanded water level band up to the bottom of the Main Steam Lines (to ensure adequate core cooling with inlet core debris clogging)
Maintain Core Cooling
References:
None Page 34 of 96
Maintain Containment (Section 13) Determine Baseline coping capability with installed coping2 modifications not including FLEX modifications, utilizing methods described in Table 3-1 of NEI 12-06:
x Containment Venting or Alternate Heat Removal x Hydrogen Igniters (Mark III containments only)
BWR Installed Equipment Phase 1:
Provide a general description of the coping strategies using installed equipment including modifications that are proposed to maintain containment integrity. Identify methods (containment vent or alternative / Hydrogen Igniters) and strategy (ies) utilized to achieve this coping time.
During Phase 1, the primary strategy is to control reactor parameters so as not to challenge containment limits within the first 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> of the event to give time to deploy cooling pumps for Phase 2. Reactor pressure is lowered at near the maximum cooldown rate to ensure that if there were an unplanned rapid depressurization during this interval, the heat rejected from the reactor system to the containment would not exceed the ability of the Hardened Containment Vent System (HCVS) to mitigate the event on a single unit.
The current as-designed HCVS is capable preventing the pressure in the pressure suppression chamber (torus) from exceeding the primary containment pressure limit of 56 psig, for a single unit, by releasing 1% of thermal power for the BFN units which have been upgraded to 3458 MWt. This vent will later be modified in accordance with the schedule for NRC Order EA 109 Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions. Concurrent with the issuance of NRC Order EA-12-049, the NRC issued Order EA-12-050 Order Modifying Licenses with Regard to Reliable Hardened Containment Vents and the NRC rescinded this order with issuance of NRC Order EA-13-109. The revised schedule and implementation timeline contained in NRC Order EA-13-109 impacts the ability to achieve full implementation of the mitigations strategy requirements of NRC Order EA-12-049 with respect to the current required dates for BFN Units 2 and 3. Relaxation and request for extension of the requirements contained in NRC Order EA-12-049 will be forthcoming in a separate correspondence. It is intended that BFN Unit 1 will comply with the timeline required by NRC Order EA-12-049 and EA-13-109. In the interim, BFN will utilize the hardened vent as currently installed and in accordance with existing procedures. (Ref. 2). (Open Item, OI 11)
Anticipatory venting utilizing the hardened wetwell vent will be performed during the first 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> of the event based on following the operational strategies in GEH Evaluation of FLEX Implementation Guidelines (Ref. 1) and preliminary MAAP analysis performed for a single unit. Procedures would caution that venting during this timeframe, if required, must be minimized to avoid an adverse impact on Reactor Core Isolation Cooling (RCIC) Net Positive 2
Coping modifications consist of modifications installed to increase initial coping time, i.e., generators to preserve vital instruments or increase operating time on battery powered equipment.
Page 35 of 96
Suction Head (NPSH) (if RCIC must be aligned to the suppression pool rather than the Condensate Storage Tank (CST)). RCIC is the only credited vessel makeup during Phase 1.
Emergency Operating Instructions contain sufficient guidance to ensure this condition is monitored and controlled.
Containment parameters will be monitored during Phase 1, initially powered by batteries, until additional air cooled diesel backed power systems are started and aligned to power the battery chargers.
Maintain Containment Details:
(Section 13a) Confirm that procedure/guidance exists or will be developed to support Provide a brief implementation description of Procedures /
Strategies /
Guidelines Browns Ferry Nuclear Plant will utilize the industry developed guidance from the Owners Groups, EPRI and NEI Task team to develop site specific procedures or guidelines to address the criteria in NEI 12-06 (Ref. 3). These procedures and/or guidelines will support the existing symptom based command and control strategies in the current EOIs (Open Item, OI 17).
(Section 13b) List modifications Identify modifications Hardened Containment Vent System (HCVS) (i.e., Reliable Hardened Vent) is currently installed but will be enhanced in accordance with the schedule for NRC Order EA-13-109. The current hardened vent is sized to protect a single unit and will be utilized in the interim as currently installed. (Ref. 2) (Open Item, OI 11).
1,2,3-LI-64-159A & 1,2,3-64-159B, Torus Level Div. I & 2, will be modified to be DC backed up instruments.
1,2,3-TI-64-52AB, Drywell Temperature, will be modified to be DC backed up instruments.
Page 36 of 96
(Section 13c) Key List instrumentation credited for this coping evaluation.
Containment Parameters Containment Essential Instrumentation Safety Function x 1,2,3-PI-64-67B, Drywell Pressure Containment integrity x 1,2,3-TI-64-52AB, Drywell Temperature x 1,2,3-LI-1,2,3-LI-64-159A, Wide Range Torus Level or x 1,2,3-LI-1,2,3-LI-64-159B, Wide Range Torus Level x 1,2,3-TI-64-161, Suppression Pool Temperature or x 1,2,3-TI-64-162, Suppression Pool Temperature The instrumentation listed above is supplied power via the Class 1 Safety Related Batteries and are located in the Main Control Room. A reference source for the plant operators will be developed that provides approaches to obtaining necessary instrument readings to support the implementation of the coping strategy (NE 12-06, Section 3.2.1.1 0). This reference source should include control room and non-control room readouts and should also provide guidance on how and where to measure key instrument readings at containment penetrations, where applicable, using a portable instrument (e.g., a Fluke meter). Such a resource could be provided as an attachment to the plant procedures/guidance. Guidance will include critical actions to perform until alternate indications can be connected and on how to control critical equipment without associated control power (Open Item, OI 5). Browns Ferrys evaluation of the FLEX strategy may identify additional parameters that are needed in order to support key actions identified in the plant procedures/guidance or to indicate imminent or actual core damage (NEI 12-06 Rev. 0 Section 3.2.1.10) and any differences will be provided in a future 6-month update following identification.
References:
- 1. GEH Evaluation of FLEX Implementation Guidelines, NEDC-33771P, Revision 0
- 2. "BWR Mark I & II Reliable Hardened Containment Vents capable of Operation Under Severe Accident Conditions", EA-13-109
- 4. Unit 1,2,3 Technical Requirements Manual Bases 3.3.3.1, Post Accident Monitoring (PAM) Instrumentation
- 5. 1,2,3-AOI-57-5A, Loss of I&C Bus A, to the reference section of Section 13
- 6. 1,2,3-AOI-57-5B, Loss of I&C Bus B, to the reference section of Section 13
None Maintain Containment (Section 14) BWR Portable Equipment Phase 2:
Provide a general description of the coping strategies using on-site portable equipment including modifications that are proposed to maintain containment integrity. Identify methods (containment vent or alternative / Hydrogen Igniters) and strategy (ies) utilized to achieve this coping time.
During Phase 1, plant personnel will started deployment of FLEX equipment. For flood events, the equipment is staged many hours before the peak flood waters exceed the design basis (see Attachment 1A). For other events, equipment is placed in service beginning with the Station Blackout (SBO) condition - in some cases, before an Extended Loss of AC Power (ELAP) is declared (see timeline, Attachment 1A).
Portable equipment and containment vent strategies are as follows:
- 1) Two redundant 850kw, 480v FLEX Generators will be permanently staged in the FESB to meet N+1 requirements. They are protected for all of the extreme natural events in Section
- 1. These will be available during Phase 2; by connection directly to the input supply breaker to the chargers. It is currently estimated that the primary 480 FLEX Generator will be deployed and connected within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />. A single generator has sufficient capacity to supply three safety related 250v battery chargers via a load control center that will be used for distribution. At this point, the Class 1 250v DC safety related battery chargers are now recovered. (Refer to Attachment 3, Figure 1)
- 2) Two 1.1MWe, 4kv FLEX Support Generators will be permanently staged in the FESB. It is currently estimated that these generators can be deployed within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. They would be used to energized the safety related 4kv distribution system and energize loads such as 120v ac instrumentation, ventilation, pump motors and motor operated valves.
- 3) Each FLEX Pumping System (FPS1, FPS2, FPS3, FPS+1) consists of a portable FLEX Low Pressure Pump (FLPP) driven by a 600 HP diesel pump rated at 5000 gpm at 150 psi discharge head and a FLEX Floating Booster Pump (FLBP). The FLBP is an integrated, transportable pumping module capable of providing up to 5,000 gpm of water at 90 ft. total dynamic head. The system utilizes two floating submersible pumps, designated satellite pumps, to supply water from an open source to a remote high-capacity pumping system, located as high as 50 ft. above and 150 ft. away in distance. A 300 hp diesel engine powers Page 38 of 96
Maintain Containment (Section 14) BWR Portable Equipment Phase 2:
the hydraulic system. Two engine mounted variable displacement pumps provide pressurized hydraulic fluid to the satellite pump motors through 150 ft. hose lines. The hose lines are retrieved and stored on two hose reels driven independently by electric motors. An electronic engine management system controls and monitors the engine and provides the operator with real time supervision of all critical engine parameters and hydraulic conditions (Refer to Attachment 3, Figure 5). TVA is designing deployment locations for the pumps, including ramps, winches or other transfer assemblies as necessary to deploy all pumps and hoses within the Phase 1 coping interval. The staff begins deployment of these pumps as soon as SBO occurs rather than waiting to exhaust all attempts to restore the emergency electric supply system. It is currently estimated that FPS1, FPS2 and FPS3 will be deployed and connected to provide backup RPV, SFP and Containment level addition at approximately 6, 7, and 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> respectively into the event. The staff begins deployment of these pumps as soon as SBO occurs rather than waiting to exhaust all attempts to restore the emergency electric supply system.
a) FLEX Pumping Systems are assigned as follows.
i) FPS1 can be connected to one or more of the following:
(1) Three Containment Integrated Leak Rate Test (CILRT) penetrations through Reactor Building wall, elevation 565' (4" pipe) - inside 1A, 2A, 3A RHRSW pipe tunnel, (From inside the Reactor Building, connections can be made to the Condensate Storage & Supply System and then to the vessel through RHR Loop I & II LPCI injection lines and Core Spray Loop I & II injection lines, to SFP makeup (normal), or to the Containment and Torus via their respective RHR Loop I and II flowpaths),
(2) The EECW South header - At the intake structure (The EDGs will be isolated by manual action if needed to ensure adequate cooling to operating SSCs). The south header can be used for SFP makeup and for all normally supplied loads with the exception of the control air compressors.
ii) FPS2 will be aligned to B RHRSW at the following location; (1) At the intake structure, Note: The B RHRSW can provide standby coolant to Unit 2 and/or Unit 3, if needed.
iii) FPS3 will be aligned at the following location:
(1) At the intake structure, Note : The D RHRSW can provide standby coolant to Unit 1 and/or Unit 2, if needed.
iv) (FPS4) - (N+1), is a spare.
Based on Table 4.5.2-2 of GEH Evaluation of FLEX Implementation Guidelines (Ref. 4),
Summary of Analysis Results for No Containment Venting (RCIC Suction from suppression pool) with heat input from Main Steam Relief Valves (MSRVs) and from RCIC during Phase 1, Page 39 of 96
Maintain Containment (Section 14) BWR Portable Equipment Phase 2:
the primary containment temperature limit can be approached at around 8.8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />. During Phase 2, FLEX deployment provides several alternatives for managing the heat load on containment.
- 4) Anticipatory venting of the containment, primary cooling strategy, will commence within the first 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> of the event with:
a) Manual operation locally of the existing hardened wetwell vent, as currently designed
- 5) Another method is to remove heat from the reactor system (reducing containment heat addition rate):
a) Heat can be removed by running HPCI in CST to CST mode (Remove work from reactor steam heat) (If the CST is available).
i) High Pressure Coolant Injection (HPCI) battery power is provided by chargers that are diesel backed (as noted above) in Phase 2. HPCI is not run until chargers are online.
- 6) Another method is to remove heat directly from containment:
a) The Drywell Cooling system can be used with:
i) EECW supply for RBCCW system from FLEX Pumping System, FPS1, and motive supply for fans, valves, controllers, and pumps from 480v FLEX DGs, the Spare 480v FLEX DG or the 4kv FLEX Support DGs.
- 7) Makeup to the suppression pool, if required during Phase 2, provided by FLEX Pumping System, FPS2 or FPS3.
a) Spraying the drywell (and/or the wet well) may be required utilizing FLEX pumps.
This is done by:
i) Containment spray from RHRSW to RHR standby coolant crosstie, with ii) Residual Heat Removal Service Water (RHRSW) charging from FLEX Pumping Systems, FPS2 or FPS3, depending on unit.
iii) Water removal from the torus, if required, driven through RHR drain pump system using containment pressure if pump not available. May also use a special HPCI lineup - Torus to CST or Hotwell, if available. The ability to accomplish this function is still under review. (Open Item, OI 20)
Note: Spraying of the Drywell could only be performed if adequate core cooling can be insured by non-continuous injection of water to the RPV to ensure adequate core cooling. This may be difficult to satisfy, when the diesel driven FLEX pumps are the only source of RPV makeup.
RCIC may still be in service for all or part of Phase 2, especially if Torus water temperature is Page 40 of 96
Maintain Containment (Section 14) BWR Portable Equipment Phase 2:
maintained below 240 degrees F. Additionally, a modification is planned to allow use of auxiliary cooling from raw water to supply the RCIC lube oil cooler to protect turbine bearings.
Emergency procedures currently require transfer of RCIC suction supply from CST to the suppression pool, if needed, to prevent adding too much inventory to the suppression pool.
Note: In order to maximize use of suppression pool water at its coolest values, procedures are being evaluated to utilize suction from the suppression pool until the temperatures rises to above 180 degrees F; and then transfer to the CST at this point, if available.
The CST is not credited as being able to sustain all the events listed in Section 1; however, it would be used if available, because it provides additional margin before containment temperature is challenged, and it reduces the temperature of the RCIC bearing cooler. This plan addresses CST use because if the CST survives, its use requires consideration of the need for mass removal from the suppression pool. The least complicated means to remove water from the suppression pool is through the use of the hardened wetwell vent system, taking advantage of the water released via this vent path.
Details:
(Section 14a) Confirm that procedure/guidance exists or will be developed to support Provide a brief implementation description of Procedures /
Strategies /
Guidelines Browns Ferry Nuclear Plant will utilize the industry developed guidance from the Owners Groups, EPRI and NEI Task team to develop site specific procedures or guidelines to address the criteria in NEI 12-06 (Ref. 6). These procedures and/or guidelines will support the existing symptom based command and control strategies in the current EOIs (Open Item, OI 17).
(Section 14b) List modifications Identify modifications x Construct Flexible Equipment Storage Building (FESB), located above the Probable Maximum Flood (PMF) level, which is adequately protected from the hazards listed in Section 1. The storage facility(s) will be used to store support equipment and items, including the four FLEX Pumping Systems, two 480v FLEX DGs and two 4kv FLEX Support DGs. (Open Items, OI 9 and OI 10) x Provide deployment locations above the PMF for staging of the 480v FLEX DGs.
Page 41 of 96
Maintain Containment (Section 14) BWR Portable Equipment Phase 2:
x Provide deployment path modifications, as necessary to ensure paths are reliable.
x Install connection points on the B and D RHRSW piping at the Intake Structure. B header provides Unit 2 & Unit 3 compliance. D header provides Unit 1 & Unit 2 compliance. (Open Item, OI 9) x Install connection point on the South EECW header piping at the Intake Structure. This header supplies support functions not directly related to mitigating strategies for core, containment and SFP cooling on Units 1, 2 & 3. (Open Item, OI 9)
(Section 14c) Key List instrumentation credited or recovered for this coping evaluation.
Containment Parameters See instrumentation listed in Phase 1 section.
(Section 14d) Storage / Protection of Equipment :
Describe storage / protection plan or schedule to determine storage requirements Seismic List how equipment is protected or scheduled to protect Portable equipment, maintained in the FESB, and connection points required to implement this FLEX strategy will be designed to meet or exceed BFNP design basis Safe Shutdown Earthquake (SSE) protection requirements.
Flooding List how equipment is protected or scheduled to protect Note: if stored below current flood level, then ensure procedures exist to move equipment prior to exceeding flood level.
Portable equipment required to implement this FLEX strategy will be maintained in the FESB, which is sited in a suitable location(s) that is above the Probable Maximum Flood (PMF) level and, as such, is not susceptible to flooding from any source. FLEX equipment deployment paths shall maintain a minimum elevation of 565', Mean Sea Level (MSL). Plant shutdown is required when flood levels reach 558' MSL in accordance with 0-AOI-100-3 (Ref. 1b).
Updated Final Safety Analysis Report (UFSAR). Based on UFSAR Chapter 2.4A Figure 16 (Ref. 2ai) shows the plant has approximately 5 days from the time river level reaches 558' MSL to the time the water level would reach 565' MSL.
Severe Storms with List how equipment is protected or scheduled to protect High Winds Page 42 of 96
Maintain Containment (Section 14) BWR Portable Equipment Phase 2:
Portable equipment required to implement this FLEX strategy will be maintained in the FESB, which is designed to meet or exceed the licensing basis high wind hazard for BFNP.
Snow, Ice, and List how equipment is protected or scheduled to protect Extreme Cold The FESB will be evaluated for snow, ice, and extreme cold temperature effects and heating will be provided as required to assure no adverse effects on the FLEX equipment. The FESB will have a stand-alone HVAC system.
High Temperatures List how equipment is protected or scheduled to protect The FESB will be evaluated for high temperature effects and ventilation will be provided as required to assure no adverse effects on the FLEX equipment. The FESB will have a stand-alone HVAC system.
(Section 14e) Deployment Conceptual Design (Attachment 3 contains Conceptual Sketches)
Strategy Modifications Protection of connections Identify strategy including Identify modifications Identify how the connection is how the equipment will be protected deployed to the point of use.
Hardened Containment The Hardened Containment Hardened Containment Vent Vent System (HCVS) is Vent System (HCVS) is System (HCVS) is designed as designed as permanently currently installed in permanently installed equipment.
installed equipment. No accordance with requirements No connection points are deployment strategy is of Generic Letter 89-16. A required.
required. separate transmittal is being submitted to seek relaxation from the containment venting requirements of NRC Order EA-12-049, to allow compliance in accordance with the schedule for NRC Order EA-13-109.
FLEX Pumping Systems Connection points will be Pump connection points are will be deployed as shown provided within the intake protected from the hazards for all in Figures 3a and 3b. pumping station at B and events listed in Section 1.
D RHRSW headers and the Page 43 of 96
Maintain Containment (Section 14) BWR Portable Equipment Phase 2:
south EECW header. The B header ensures compliance for Unit 2 and/or Unit 3. The D header ensures compliance for Unit 1 and/or Unit 2.
Deployment locations will be 480 V FLEX DGs shall be 480v FLEX DGs will be modified to be above the PMF protected from all events listed in section 1. The Spare FLEX DG deployed as shown in Figure 3c shall be protected from all events listed in Section 1.
References:
- 1. Abnormal Operating Instructions (AOIs)
- a. 0-AOI-57-1A, Loss of Offsite Power (161 and 500 KV)/Station Blackout
- b. 0-AOI-100-3, Flood Above Elevation 558'
- 2. Browns Ferry Nuclear Plant (BFNP) Updated Final Safety Analysis Report (UFSAR)
- a. Section 2.4A,
- i. Figure 16 (Amendment 25)
- 3. Draft Interim Staff Guidance JLD-ISG-2012-01, Compliance with Order EA-12-049, Order Modifying Licenses with Regard to Requirements for Mitigating Strategies for Beyond-Design-Basis External Events; Docket ID NRC-2012-0068
- 4. GEH Evaluation of FLEX Implementation Guidelines, NEDC-33771P, Revision 0
- a. Section 7.3.1.1.b Notes:
None Maintain Containment (Section 15) BWR Portable Equipment Phase 3:
Provide a general description of the coping strategies using Phase 3 equipment including modifications that are proposed to maintain containment integrity. Identify methods (containment vent or alternative / Hydrogen Igniters) and strategy (ies) utilized to achieve this Page 44 of 96
Maintain Containment (Section 15) BWR Portable Equipment Phase 3:
coping time.
Primary (and Alternate) Strategy For Phase 3, the containment cooling maintenance strategy is initially the same as the strategy being implemented in Phase 2 (containment venting via the hardened wetwell vent in accordance with existing procedures and design).:
- 1. Phase 3 will provide additional support to continue and reinforce the Phase 2 strategy.
Phase 3 will provide (6) ~ 1 MWe Generators (2 per reactor unit), high capacity low pressure pumps with booster pump assemblies to backup FPS1, FPS2, & FPS3, additional diesel fuel, supplies and redundancy for the FLEX equipment being used. Additionally, Phase 3 will provide for demineralized water to makeup to the torus, Spent Fuel Pool (SFP),
and/or the Reactor Pressure Vessel (RPV) as necessary.
Eventually in Phase 3 or beyond, after the (6) 1 MWe RRC Generators arrive on site and are deployed and hooked up, RHR containment cooling modes can be made available utilizing an RHR pump with suction from the Torus, RHR Heat Exchanger cooling being provided by FPS2 and /or FPS3 and the RHR room Cooler and seal heat exchanger being supplied EECW cooling water from FPS1.
Details:
(Section 15a) Confirm that procedure/guidance exists or will be developed to support Provide a brief implementation description of Procedures /
Strategies /
Guidelines Same as Section 14a.
(Section 15b) List modifications Identify modifications Same as Section 14b, except that additional connection points will be provided to replace any FLEX DGs that have failed. (Open Item, OI 9)
(Section 15c) Key List instrumentation credited or recovered for this coping evaluation.
Containment Parameters Page 45 of 96
Maintain Containment (Section 15) BWR Portable Equipment Phase 3:
Same as Section 14c.
(Section 15d) Deployment Conceptual Design (Attachment 3 contains Conceptual Sketches)
Strategy Modifications Protection of connections Identify strategy Identify modifications Identify how the connection is including how the protected equipment will be deployed to the point of use.
Same as Section 14d. Same as Section 14d. Same as Section 14d.
References:
None Notes:
None Page 46 of 96
Maintain Spent Fuel Pool Cooling (Section 16) Determine Baseline coping capability with installed coping3 modifications not including FLEX modifications, utilizing methods described in Table 3-1 of NEI 12-06:
x Makeup with Portable Injection Source BWR Installed Equipment Phase 1:
Provide a general description of the coping strategies using installed equipment including modifications that are proposed to maintain spent fuel pool cooling. Identify methods (makeup with portable injection source) and strategy (ies) utilized to achieve this coping time.
The normal Spent Fuel Pool (SFP) water inventory provides sufficient SFP cooling to prevent fuel damage for the entire coping period until Phase 2 (8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />). RTM-96 Response Technical Manual, Volume 1 (Ref. 2), was used with a full core recently discharged plus 20 years of accumulated discharges, after 5 days shutdown.
x The time for the SFP to boil is 3.1 hours1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />.
x The required makeup to offset boil off is 81 gallons per minute.
x The SFP must be virtually drained for substantial damage to occur. Pools are considered coolable as long as 20% of the fuel is covered.
x Cladding failure with release of the fission products in the fuel pin gap is possible within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> to several days after the pool is drained.
x The boil dry time is estimated at 49.3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br />.
TVA will develop procedures (as shown on timeline, Attachment 1A) to deploy and secure makeup hoses at the SFP before boiling would occur. This could be required as early as 3.1 hours1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> to avoid having to access the SFP deck while boiling is in progress; however, TVA may allow for a longer time period if actual SFP loads are lower (as would normally be expected).
At eight hours into the event, more than 40 hours4.62963e-4 days <br />0.0111 hours <br />6.613757e-5 weeks <br />1.522e-5 months <br /> remain before the fuel becomes inadequately cooled.
Using realistic analysis, none of the spent fuel pools at BFN currently have greater than a 3 degree per hour heatup rate immediately following fuel shuffles. Based on being at the Tech Spec limit of 150 degrees, approximately 20 hours2.314815e-4 days <br />0.00556 hours <br />3.306878e-5 weeks <br />7.61e-6 months <br /> are available for action to be taken prior to pool boil following the ELAP and LUHS. Using the administrative limit for SFP Temperature of 125 degrees, this allows approximately 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br /> for actions to be taken. (Ref. 4) 3 Coping modifications consist of modifications installed to increase initial coping time, i.e., generators to preserve vital instruments or increase operating time on battery powered equipment.
Page 47 of 96
Maintain Spent Fuel Pool Cooling Details:
(Section 16a) Confirm that procedure/guidance exists or will be developed to support Provide a brief implementation description of Procedures /
Strategies /
Guidelines Browns Ferry Nuclear Plant will utilize the industry developed guidance from the Owners Groups, EPRI and NEI Task team to develop site specific procedures or guidelines to address the criteria in NEI 12-06 (Ref. 1). These procedures and/or guidelines will support the existing symptom based command and control strategies in the current EOIs (Open Item, OI 17).
(Section 16b) List modifications Identify modifications Modifications to install SFP level instrumentation per NRC Order EA-12-051 (Ref. 3).
(Open Item, OI 12)
(Section 16c) Key List instrumentation credited or recovered for this coping evaluation.
SFP Parameters Per NRC Order EA-12-051.
References:
- 2. NUREG/BR-0150 Vol. 1, Rev. 4, "RTM-96 Response Technical Manual, Volume 1, ML003747073
- a. Table D-1. Heatup and boil-dry times for a typical spent fuel pool
- 3. Order to Enhance Spent Fuel Pool Instrumentation, EA-12-051
- 4. 1-AOI-78-1, 2-AOI-78-1 & 3-AOI-78-1 Fuel Pool Cooling Cleanup System Failure Notes:
None Page 48 of 96
Maintain Spent Fuel Pool Cooling (Section 17) BWR Portable Equipment Phase 2:
Provide a general description of the coping strategies using on-site portable equipment including modifications that are proposed to maintain spent fuel pool cooling. Identify methods (makeup with portable injection source) and strategy (ies) utilized to achieve this coping time.
The normal Spent Fuel Pool (SFP) water inventory provides sufficient SFP cooling to prevent fuel damage for the entire Phase 1 coping period until Phase 2 (8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />); however, Plant Staff will have deployed hoses at the refuel floor, if necessary (see Section 16), to avoid having to access the refuel deck while the SFP is boiling.
During Phase 1, plant personnel will deploy Phase 2 equipment. For flood events, the equipment is staged many hours before the peak flood waters exceed the design basis (see Attachment 1A). For other events, equipment is placed in service beginning with the SBO condition - in some cases, before an ELAP is declared (see timeline, Attachment 1A).
- 1) Two redundant 850kw, 480v FLEX Generators will be permanently staged in the FESB to meet N+1 requirements. They are protected for all of the extreme natural events in Section
- 1. These will be available during Phase 2; by connection directly to the input supply breaker to the chargers. It is currently estimated that the primary 480 FLEX Generator will be deployed and connected within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />. A single DG has sufficient capacity to supply all safety related 250v battery chargers via a load control center that will be used for distribution. At this point, the Class 1 250v DC safety related battery chargers are now recovered. (Refer to Attachment 3, Figure 1)
- 2) Two 1.1MWe, 4kv FLEX Support Generators will be permanently staged in the FESB. It is currently estimated that these generators can be deployed within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. They would be used to energized the safety related 4kv distribution system and energize loads such as 120v ac instrumentation, ventilation, pump motors and motor operated valves.
- 3) Each FLEX Pumping System (FPS1, FPS2, FPS3, FPS+1) consists of a portable FLEX Low Pressure Pump (FLPP) driven by a 600 HP diesel pump rated at 5000 gpm at 150 psi discharge head and a FLEX Floating Booster Pump (FLBP). The FLBP is an integrated, transportable pumping module capable of providing up to 5,000 gpm of water at 90 ft. total dynamic head. The system utilizes two floating submersible pumps, designated satellite pumps, to supply water from an open source to a remote high-capacity pumping system, located as high as 50 ft. above and 150 ft. away in distance. A 300 hp diesel engine powers the hydraulic system. Two engine mounted variable displacement pumps provide pressurized hydraulic fluid to the satellite pump motors through 150 ft. hose lines. The hose lines are retrieved and stored on two hose reels driven independently by electric motors. An electronic engine management system controls and monitors the engine and provides the operator with real time supervision of all critical engine parameters and hydraulic conditions (Refer to Attachment 3, Figure 5). TVA is designing deployment locations for the pumps, including ramps, winches or other transfer assemblies as necessary to deploy all pumps and hoses within the Phase 1 coping interval. The staff begins deployment of these pumps as soon as SBO occurs rather than waiting to exhaust all attempts to restore the Page 49 of 96
Maintain Spent Fuel Pool Cooling (Section 17) BWR Portable Equipment Phase 2:
emergency electric supply system. It is currently estimated that FPS1, FPS2 and FPS3 will be deployed and connected to provide backup RPV, SFP and Containment level addition at approximately 6, 7, and 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> respectively into the event. The staff begins deployment of these pumps as soon as SBO occurs rather than waiting to exhaust all attempts to restore the emergency electric supply system.
a) FLEX Pumping Systems are assigned as follows.
i) FPS1 can be connected to one or more of the following:
(1) Three Containment Integrated Leak Rate Test (CILRT) penetrations through Reactor Building wall, elevation 565' (4" pipe) - inside 1A, 2A, 3A RHRSW pipe tunnel, (From inside the Reactor Building, connections can be made to the Condensate Storage & Supply System and then to the vessel through RHR Loop I & II LPCI injection lines and Core Spray Loop I & II injection lines, to SFP makeup (normal), or to the Containment and Torus via their respective RHR Loop I and II flowpaths),
(2) The EECW South header - At the intake structure (The EDGs will be isolated by manual action if needed to ensure adequate cooling to operating SSCs). The south header can be used for SFP makeup and for all normally supplied loads with the exception of the control air compressors.
ii) FPS2 will be aligned to B RHRSW at the following location; (1) At the intake structure, Note: The B RHRSW can provide standby coolant to Unit 2 and/or Unit 3, if needed, and route water to the SFP via RHR to SFP alignment per 2-OI-74 (RHR Operating Instruction).
iii) FPS3 will be aligned at the following location:
(1) At the intake structure.
Note : The D RHRSW can provide standby coolant to Unit 1 and/or Unit 2, if needed, and route water to the SFP via RHR to SFP alignment per 2-OI-74 (RHR Operating Instruction).
iv) (FPS4) - (N+1), is a spare.
SFP level instrumentation will be provided in accordance with NRC Order EA-12-051 (Ref. 4)
(Open Item, OI 12)
Primary Strategy when SFP heat load is high (early in cycle after an offload).
The fuel pool makeup requirements will be met by connecting the EECW makeup line to the SFP through the hoses previously aligned on the refuel deck. The EECW system will be charged using FLEX Pumping System, FPS1. A second alternative (N + 1) is to inject flow from FLEX Pumping System, FPS2 or FPS3 (depending on unit) via the RHR standby coolant alignment to RHR SFP makeup. . A third alternative can utilized FPS1 or FPS2 to charge the CS&S system via the 4 CILRT connections and providing makeup through the normal flow path the SFP skimmer surge tank.
Page 50 of 96
Maintain Spent Fuel Pool Cooling (Section 17) BWR Portable Equipment Phase 2:
Strategies when SFP heat load is low (late in core life)
When SFP heat load is low, SFP cooling is not needed until after Phase 3 begins. If SFP makeup or cooling is needed before Phase 3, these same strategies would be implemented, only later.
(Section 17a) Confirm that procedure/guidance exists or will be developed to support Provide a brief implementation description of Procedures /
Strategies /
Guidelines Browns Ferry Nuclear Plant will utilize the industry developed guidance from the Owners Groups, EPRI and NEI Task team to develop site specific procedures or guidelines to address the criteria in NEI 12-06 (Ref. 3). These procedures and/or guidelines will support the existing symptom based command and control strategies in the current EOIs (Open Item, OI 17).
(Section 17b) List modifications Identify modifications x Modification to install SFP level instrumentation per NRC Order EA-12-051 (Ref. 4).
(Open Item, OI 12) x FESB to store equipment (i.e., FLEX pumps, hoses, DGs, transport equipment, ramps to river, diesel fuel transfer pump systems) as described above.
(Section 17c) Key List instrumentation credited or recovered for this coping evaluation.
SFP Parameters NRC Order EA-12-051, Spent Fuel Pool Level instrumentation. (Ref. 4) (Open Item 12, OI-12)
(Section 17d) Storage / Protection of Equipment :
Describe storage / protection plan or schedule to determine storage requirements Seismic List how equipment is protected or scheduled to protect The permanent piping system used to provide water from the intake structure to the plant is the RHRSW piping which is seismically qualified. FLEX pumps will be stored in storage structures designed and constructed to meet the requirements of NEI 12-06 (Ref. 3).
Portable equipment, maintained in the FESB, and connection points required to implement this FLEX strategy will be designed to meet or exceed BFNP design basis Safe Shutdown Page 51 of 96
Maintain Spent Fuel Pool Cooling (Section 17) BWR Portable Equipment Phase 2:
Earthquake (SSE) protection requirements.
Flooding List how equipment is protected or scheduled to protect Note: if stored below current flood level, then ensure procedures exist to move equipment prior to exceeding flood level.
Portable equipment required to implement this FLEX strategy will be maintained in the FESB, which is sited in a suitable location that is above the Probable Maximum Flood (PMF) level and, as such, is not susceptible to flooding from any source. FLEX equipment deployment paths shall maintain a minimum elevation of 565', Mean Sea Level (MSL). Plant shutdown is required when flood levels reach 558' MSL in accordance with 0-AOI-100-3 (Ref. 1b).
Updated Final Safety Analysis Report (UFSAR) Chapter 2.4A Figure 16 (Ref. 2ai) shows the plant has approximately 5 days from the time river level reaches 558' MSL to the time the water level would reach 565' MSL.
Severe Storms with List how equipment is protected or scheduled to protect High Winds "The piping used to provide makeup flow to the SFP is contained within buildings that are protected from storms and high winds. Portable equipment required to implement this FLEX strategy will be maintained in the FESB, which is designed to meet or exceed the licensing basis high wind hazard for BFNP.
Snow, Ice, and List how equipment is protected or scheduled to protect Extreme Cold The piping used to provide makeup flow to the SFP is contained within buildings that are protected from snow, ice, and extreme cold. The FESB will be evaluated for snow, ice, and extreme cold temperature effects and heating will be provided as required to assure no adverse effects on the FLEX equipment. The FESB will have a stand-alone HVAC system.
High Temperatures List how equipment is protected or scheduled to protect The piping used to provide makeup flow to the SFP is contained within buildings that are protected from high temperatures. The FESB will be evaluated for high temperature effects and ventilation will be provided as required to assure no adverse effects on the FLEX equipment.
The FESB will have a stand-alone HVAC system.
Page 52 of 96
Maintain Spent Fuel Pool Cooling (Section 17e) Deployment Conceptual Design (Attachment 3 contains Conceptual Sketches)
Strategy Modifications Protection of connections Identify strategy including Identify modifications Identify how the connection is how the equipment will be protected deployed to the point of use.
Three FLEX Pumping Systems will be deployed to supply river water into existing systems.
x FLEX Pumping x Install hose x Install hose connections sized for System (FPS1) will be connections sized for FPS1 on the EECW header that deployed to supply FPS1 on the EECW will be connected to the South water into the South header that will be EECW header at the intake EECW header via connected to the South pumping station. This connection installed connections EECW header at the will be protected equivalent to at the intake pumping intake pumping the safety related EECW header.
station. station.
x FLEX Pumping x Install hose x Install hose connections sized for System (FPS2) will be connections sized for FPS2 on the RHRSW B header deployed to supply FPS2 on the RHRSW at the intake pumping station.
water into the B header at the This connection will be protected RHRSW B header intake pumping equivalent to the safety related via installed station. B header RHRSW header connections at the provides Unit 2 &
intake pumping Unit 3 compliance.
station. D header provides Unit 1 & Unit 2 compliance.
x FLEX Pumping x Install hose x Install hose connections sized for System (FPS3) will be connections sized for FPS3 on the RHRSW D header deployed to supply FPS3 on the RHRSW at the intake pumping station.
water into the D header at the This connection will be protected RHRSW D header intake pumping equivalent to the safety related via installed station. RHRSW header connections at the Page 53 of 96
intake pumping station.
x A second arrangement x The second would have a FLEX arrangement through Pumping System the ILRT penetration supply water through requires no the Containment modifications.
Integrated Leak Rate Test (CILRT) connection in the RHRSW Tunnel 1A, running hoses in the Reactor Building to the Condensate Storage and Supply connections: which then, could be valved-in to supply water to the SPF.
x Portable fuel transfer x Modifications may be Diesel generator 7-day tanks are pumps will remove performed to facilitate located underneath the safety related fuel from the access to the Diesel Diesel Generators and protected Emergency Diesel Generator 7 day tanks from all the conditions listed in NEI Generator 7-day tanks and facilitate portable 12-06, Section 1. The deployment to fill equipment fuel fuel transport pump trucks and portable fuel transfer tanks. Deployment connection. pumps will be stored in the FESB trucks (5500 series) which is protected from all the will also be equipped conditions listed in NEI 12-06, with a fuel storage Section 1.
tank to transport fuel to locations in need of fuel.
Page 54 of 96
Maintain Spent Fuel Pool Cooling
References:
- 1. Abnormal Operating Instructions (AOIs)
- a. 0-AOI-57-1A, section 4.2
- b. 0-AOI-100-3, Flood Above Elevation 558'
- 2. Browns Ferry Nuclear Plant (BFNP) Updated Final Safety Analysis Report (UFSAR)
- a. Section 2.4A
- i. Figure 16 (Amendment 25)
- 4. Order to Enhance Spent Fuel Pool Instrumentation, EA-12-051 Notes:
None Maintain Spent Fuel Pool Cooling (Section 18) BWR Portable Equipment Phase 3:
Provide a general description of the coping strategies using Phase 3 equipment including modifications that are proposed to maintain spent fuel pool cooling. Identify methods (makeup-with portable injection source) and strategy (ies) utilized to achieve this coping time.
The industry will establish two Regional Response Centers (RRC) to provide support to utilities during the beyond-design-basis events. Each RRC will hold five sets of equipment, four of which will be able to be fully deployed when requested, the fifth set will have equipment in a maintenance cycle. Equipment will be moved from an RRC to a local Assembly Area, established by the SAFER team and the utility. Communications will be established between the affected nuclear site and the SAFER team and required equipment will be moved to the site as needed. First arriving equipment, as established during development of the BFNP playbook (the Regional Response Centers plan for coordinating with each utility), will be delivered to the site within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> from the initial request. The Browns Ferry Nuclear Plant Playbook will establish appropriate requirements for additional fuel and consumables to support the in-process Phase 2 strategies and will provide additional backup for extended operation of the Phase 2 strategies. In addition, the Phase 3 BFNP Playbook will include provisions for recovery facilities (i.e., demineralized water supply & (6) 1 MWe Generators). TVA is working with the Nuclear Industry to develop standard requirements for RRC response. More details regarding the BFNP Phase 3 Playbook and the Regional Response Centers will be provided in later updates (Open Item, OI 19).
Page 55 of 96
Maintain Spent Fuel Pool Cooling (Section 18) BWR Portable Equipment Phase 3:
The following Phase 2 equipment will continue to be used in Phase 3 if it is still required for spent fuel cooling.
- 1) Two redundant 850kw, 480v FLEX Generators will be permanently staged in the FESB to meet N+1 requirements. They are protected for all of the extreme natural events in Section
- 1. These will be available during Phase 2; by connection directly to the input supply breaker to the chargers. It is currently estimated that the primary 480 FLEX Generator will be deployed and connected within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />. A single DG has sufficient capacity to supply all safety related 250v battery chargers via a load control center that will be used for distribution. At this point, the Class 1 250v DC safety related battery chargers are now recovered. (Refer to Attachment 3, Figure 1)
- 2) Two 1.1MWe, 4kv FLEX Support Generators will be permanently staged in the FESB. It is currently estimated that these generators can be deployed within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. They would be used to energized the safety related 4kv distribution system and energize loads such as 120v ac instrumentation, ventilation, pump motors and motor operated valves.
- 3) Each FLEX Pumping System (FPS1, FPS2, FPS3, FPS+1) consists of a portable FLEX Low Pressure Pump (FLPP) driven by a 600 HP diesel pump rated at 5000 gpm at 150 psi discharge head and a FLEX Floating Booster Pump (FLBP). The FLBP is an integrated, transportable pumping module capable of providing up to 5,000 gpm of water at 90 ft. total dynamic head. The system utilizes two floating submersible pumps, designated satellite pumps, to supply water from an open source to a remote high-capacity pumping system, located as high as 50 ft. above and 150 ft. away in distance. A 300 hp diesel engine powers the hydraulic system. Two engine mounted variable displacement pumps provide pressurized hydraulic fluid to the satellite pump motors through 150 ft. hose lines. The hose lines are retrieved and stored on two hose reels driven independently by electric motors. An electronic engine management system controls and monitors the engine and provides the operator with real time supervision of all critical engine parameters and hydraulic conditions (Refer to Attachment 3, Figure 5). TVA is designing deployment locations for the pumps, including ramps, winches or other transfer assemblies as necessary to deploy all pumps and hoses within the Phase 1 coping interval. The staff begins deployment of these pumps as soon as SBO occurs rather than waiting to exhaust all attempts to restore the emergency electric supply system. It is currently estimated that FPS1, FPS2 and FPS3 will be deployed and connected to provide backup RPV, SFP and Containment level addition at approximately 6, 7, and 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> respectively into the event. The staff begins deployment of these pumps as soon as SBO occurs rather than waiting to exhaust all attempts to restore the emergency electric supply system.
b) FLEX Pumping Systems are assigned as follows.
i) FPS1 can be connected to one or more of the following:
(1) Three Containment Integrated Leak Rate Test (CILRT) penetrations through Reactor Building wall, elevation 565' (4" pipe) - inside 1A, 2A, 3A RHRSW pipe tunnel, (From inside the Reactor Building, connections can be made to the Page 56 of 96
Maintain Spent Fuel Pool Cooling (Section 18) BWR Portable Equipment Phase 3:
Condensate Storage & Supply System and then to the vessel through RHR Loop I & II LPCI injection lines and Core Spray Loop I & II injection lines, to SFP makeup (normal), or to the Containment and Torus via their respective RHR Loop I and II flowpaths),
(2) The EECW South header - At the intake structure (The EDGs will be isolated by manual action if needed to ensure adequate cooling to operating SSCs). The south header can be used for SFP makeup and for all normally supplied loads with the exception of the control air compressors.
ii) FPS2 will be aligned to B RHRSW at the following location; (1) At the intake structure, Note: The B RHRSW can provide standby coolant to Unit 2 and/or Unit 3, if needed.
iii) FPS3 will be aligned at the following location:
(1) At the intake structure, Note : The D RHRSW can provide standby coolant to Unit 1 and/or Unit 2, if needed.
iv) (FPS4) - (N+1), is a spare.
SFP level instrumentation will be provided in accordance with NRC Order EA-12-051 (Ref. 3)
(Open Item, OI 12)
Primary Strategy when SFP heat load is high (early in cycle after an offload).
An RHR pump, powered by FLEX generators provided by the RRC, can be aligned to SFP cooling assist mode to provide SFP cooling. Residual Heat Removal (RHR) can also provide makeup to the SFP (torus temperatures would be maintained below boiling since unit heat load will be low). Residual Heat Removal (RHR) room and seal coolers will be supported by FLEX Pumping System, FPS1 (via EECW system piping). FLEX Pumping Systems, FPS2 or FPS3 will provide river cooling supply to the RHR heat exchangers.
The Fuel Pool Cooling and Cleanup (FPCCU) system can be operated with power from a FLEX DG(s) from the RRC. FLEX Pumping System, FPS1 provides cooling water for the Reactor Building Closed Cooling Water System (RBCCW) Heat Exchanger (HTX) which, in turn, supplies cooling to the FPCCU HTXs.
Other strategies may be developed based on equipment supplied from the RRC (i.e., makeup pumps, demineralized water system, portable heat exchangers, and restoration of Auxiliary Decay Heat Removal System (ADHR)). If developed, these will be provided in later updates.
Schedule:
(Section 18a) Confirm that procedure/guidance exists or will be developed to support Provide a brief implementation description of Page 57 of 96
Maintain Spent Fuel Pool Cooling (Section 18) BWR Portable Equipment Phase 3:
Procedures /
Strategies /
Guidelines Browns Ferry Nuclear Plant will utilize the industry developed guidance from the Owners Groups, EPRI and NEI Task team to develop site specific procedures or guidelines to address the criteria in NEI 12-06 (Ref. 2). These procedures and/or guidelines will support the existing symptom based command and control strategies in the current EOIs (Open Item, OI 17).
(Section 18b) List modifications Identify modifications Modification to install SFP level instrumentation per NRC Order EA-12-051 (Ref. 3).
(Section 18c) Key List instrumentation credited or recovered for this coping evaluation.
SFP Parameter SFP Level per Order EA-12-051 (Ref. 3).
(Section 18d) Deployment Conceptual Design (Attachment 3 contains Conceptual Sketches)
Strategy Modifications Protection of connections Identify strategy Identify modifications Identify how the connection is including how the protected equipment will be deployed to the point of use.
See Phase 2 discussion, See Phase 2 discussion, Section See Phase 2 discussion, Section Section 17 17 17
References:
- 1. Abnormal Operating Instructions (AOIs)
- a. 0-AOI-57-1A, section 4.2
- 3. Order to Enhance Spent Fuel Pool Instrumentation, EA-12-051 Notes:
None Page 58 of 96
Safety Functions Support (Section 19) Determine Baseline coping capability with installed coping4 modifications not including FLEX modifications.
BWR Installed Equipment Phase 1 Provide a general description of the coping strategies using installed equipment including station modifications that are proposed to maintain and/or support safety functions. Identify methods and strategy (ies) utilized to achieve coping times.
Main Control Room Habitability Under ELAP conditions with no mitigating actions taken, initial analysis projects the control room to approach 110°F (the assumed maximum temperature for efficient human performance) in a time of approximately 19 hours2.199074e-4 days <br />0.00528 hours <br />3.141534e-5 weeks <br />7.2295e-6 months <br /> (U1/U2) and 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> (U3). Phase 1 FLEX strategy is to block open the entrance door to the Main Control Room (MCR) when the MCR temperature reaches 94°F (U1/U2) and 93°F (U3) (the assumed outside temperature at the time of event occurrence). This will establish a flow path for air to flow from the control building (and outside) to the MCR. The preliminary assessment indicates that by employing this strategy the MCR temperature will rise to approximately 101°F (U1/U2) and 99 °F (U3) at the 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> point by which time Phase 2 actions can be implemented, NEI 12-06 (Ref. 2).
RCIC Room Habitability Under the Station Blackout (SBO) case the temperature remains below 127°F for the entire transient of 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />. To determine the temperature impact to the pump rooms over an extended period, the curves in the above assessment were extrapolated to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. The extrapolation indicated that temperature in the pump rooms will rise to a maximum of approximately 151°F in approximately 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.
At approximately 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />, FLEX pumps are available for service allowing RCIC to be shutdown, if necessary, GEH Evaluation of FLEX Implementation. Guidelines (Ref. 1)
For the purposes of NEI 12-06 (Ref. 2), it is not anticipated that continuous habitability would be required in the pump rooms. If personnel entry is required into the pump room, then personal protective measures such as ice vests will be taken in accordance with Site Administrative and Safety Procedures and Processes.
Other areas/rooms listed in Loss of HVAC During ELAP (Ref. 3) at BFNP were evaluated. The rooms selected contain equipment necessary and/or desired for coping with emergency plant functions during an ELAP condition. These areas are not anticipated to require continuous habitability and personal protective measures will be implemented in accordance with Site Administrative and Safety Procedures and Processes.
4 Coping modifications consist of modifications installed to increase initial coping time, i.e., generators to preserve vital instruments or increase operating time on battery powered equipment.
Page 59 of 96
Safety Functions Support Details:
(Section 19a) Confirm that procedure/guidance exists or will be developed to support Provide a brief implementation description of Procedures /
Strategies /
Guidelines Browns Ferry Nuclear Plant will utilize the industry developed guidance from the Owners Groups, EPRI and NEI Task team to develop site specific procedures or guidelines to address the criteria in NEI 12-06 (Ref. 2). These procedures and/or guidelines will support the existing symptom based command and control strategies in the current EOIs (Open Item, OI 17).
(Section 19b) List modifications Identify modifications No modifications are required to support implementation of portable equipment Phase 1.
Modifications that are required will be described upon future design reviews that are controlled by the utility Standard Programs and Processes (SPPs).
(Section 19c) Key List instrumentation credited for this coping evaluation phase.
Parameter Battery operated portable temperature instruments are available from the BFNP tool room.
These are used during normal plant operation to monitor local conditions during HVAC /chiller maintenance outages and would be available, if needed to monitor temperature in critical areas of the plant, including the MCR.
A set of required portable temperature instrumentation will be identified as required FLEX equipment and will be maintained accordingly.
References:
- 1. GEH Evaluation of FLEX Implementation Guidelines, NEDC-33771P, Revision 0
None Page 60 of 96
Safety Functions Support (Section 20) BWR Portable Equipment Phase 2 Provide a general description of the coping strategies using on-site portable equipment including station modifications that are proposed to maintain and/or support safety functions. Identify methods and strategy (ies) utilized to achieve coping times.
Main Control Room Habitability Primary Strategy
The primary strategy for maintaining the environment of the Main Control Room (MCR) during Phase 2 will be the employment of portable fans.
x One fan blowing air at the outdoor temperature into the U1/U2 MCR 617.0-C12.
x One fan blowing air at the outdoor temperature into the U3 MCR 617.0-C19.
Temporary duct could be run from outside, through the Turbine Building, through the Corridor, and into the MCR. Power for the fans will be determined at a later date.
For the MCR areas, a breach of the Main Control Room Habitability Zone (MCRHZ) boundary and addition of temporary fans can be utilized to reduce temperatures in the MCR areas.
Installation of supply and discharge flexible ductwork on the fans and locating the fans accordingly can reduce noise in the MCR areas.
RCIC Room Habitability Primary Strategy The primary strategy for maintaining the environment of the RCIC room will use the same strategy as in Phase 1, section 19. Based on extrapolation of the heat up curves, temperature in the RCIC room will rise to approximately 151°F in approximately 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.
At approximately 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />, FPS2 and FPS3 are in service allowing RCIC to be shutdown, at which time the RCIC room will be at approximately 126°F Browns Ferry Post Fukushima FLEX Response Evaluation (Ref. 2); thus, RCIC room temperature is maintained well below equipment design limits during RCIC operations in Phase 1, Phase 2, and Phase 3.
It is not anticipated that habitability of the RCIC room will be required; however, if personnel habitability becomes necessary then personal protective measures will be implemented in accordance with Site Administrative and Safety Procedures and Processes.
RHR / CS Room Habitability Under the Station Blackout (SBO) case the temperature remains below 120°F for the entire transient of 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />. To determine the temperature impact to the pump rooms over an extended period, the curves in the above calculation were extrapolated to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. The extrapolation indicated that temperature in the pump rooms will rise to a maximum of approximately 145°F Page 61 of 96
Safety Functions Support (Section 20) BWR Portable Equipment Phase 2 in approximately 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.
At 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> after the Event initiation it is assumed that the FLEX Pumping Systems are deployed for service with hoses aligned.
x B and D RHRSW headers are charged from FLEX Pumping Systems, FPS2 and FPS3.
x EECW headers charged from FLEX Pumping System, FPS1.
x Water is available on elevation 565 of each Reactor via lines from FLEX Pumping System, FPS1.
x One spare FLEX Pumping System, FPS4, is also potentially available.
For the purposes of NEI 12-06, it is not anticipated that continuous habitability would be required in the pump rooms. If personnel entry is required into the pump room, then personal protective measures such as ice vests will be taken in accordance with Site Administrative and Safety Procedures and Processes.
Engineered Safety Feature (ESF) Switchgear Rooms For Phase 2, the rooms containing the 480 VAC ESF switchgear will be begin to heat up if the switchgear is energized by a 480v FLEX DG; therefore, they were evaluated for limiting temperatures for equipment survivability. The calculations performed in Loss of HVAC During ELAP (Ref. 7) indicate that switchgear rooms rise to 90°F at the end of a four hour coping period. Under ELAP conditions, the units switchgear are de-energized at the onset of the ELAP and remain de-energized until Phase 2 when portions of the switchgear may be reenergized by the 480v FLEX DGs or the 4kv FLEX Support DGs. The rooms will begin to heat up in Phase 2, following the energization of some 480 VAC switchgear and therefore, a coping period for the duration of Phase 2 must be considered.
An acceptable strategy for heat removal from the switchgear rooms is the establishment of a method to exhaust the heat to the outside by means of portable exhaust fans. Note that the 4160 VAC switchgear is not energized during the Phase 1 coping period.
Normal air conditioning and ventilation can be restored to these rooms following the energization of the safety related electrical boards by the 4kv FLEX Support Generators.
Battery Room Ventilation During battery charging operations in Phase 2 and 3, ventilation is required in the main battery rooms due to hydrogen generation. The battery rooms were evaluated for heat loads and it was determined that the resultant temperature rise is negligible, Loss of HVAC During ELAP (Ref. 1). The calculation of battery room hydrogen generation determined that hydrogen levels will not reach two percent until 29.9 hours1.041667e-4 days <br />0.0025 hours <br />1.488095e-5 weeks <br />3.4245e-6 months <br /> assuming charging starts at time 0 and Battery room initial temperature is at 110°F with equalizing voltage at 2.33 volts Loss of HVAC During Page 62 of 96
Safety Functions Support (Section 20) BWR Portable Equipment Phase 2 ELAP (Ref. 1).
A shallow load shed can be performed that extends the Unit Battery life to no less than 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> with minimal load shedding. When the identified loads are shed from Unit Batteries 1, 2, and 3 it is expected that BFNP will achieve a 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> Unit Battery discharge duration Browns Ferry Post Fukushima FLEX Response Evaluation (Ref. 2). The batteries will be placed on charge in Phase 2 before the discharge duration runs out. (Open Item, OI 6)
Hydrogen generation does not occur unless the batteries are on charge. Phase 2 strategies can provide power both for charging and to supply power for room ventilation There are two strategies for venting the battery rooms. The primary strategy is to prop open doors and set up portable fans. The alternate strategy is to repower the existing emergency exhaust fans which are connected to the Emergency Power bus. This will occur if the 4kv FLEX Support Generator has been connected to power the 4kv distribution system..
Spent Fuel Pool Area The Spent Fuel Pool (SFP) area for BFNP is a common area for all three units. Normal HVAC is supplied from fans located on grade level on the south side of the Reactor Building. The Reactor Building Heating and Ventilating System (HVAC) is shut down and isolated when that zone of secondary containment is isolated and connected to the SGTS. For steam line failures in the Reactor Building, Updated Final Safety Analysis Report (UFSAR) Section 5-5.3 (Ref.
3b) but outside the drywell and outside the main steam valve room, the pressure would be relieved to the refueling room by the hatches and hatchways. The pressure within secondary containment would then be relieved to the large blowout panels in the insulated metal siding.
Therefore, there would be no manual actions required to relieve pressure during an ELAP.
Ventilation of the refuel floor, elevation 664.0', during an ELAP can be established by opening doors to the vent tower and vent tower roof of units 1 and 3. The equipment hatches for each unit will always have a minimum opening area and allow air from the lower floors to rise and be released through the open doors to the vent tower, Updated Final Safety Analysis Report (UFSAR) Section 5-5.3 (Ref. 3a).
Spent Fuel Pool Gate Seals Removable gates are provided at the transfer canal of the SFP to facilitate movement of fuel during refueling operations. The gates have non-inflatable (rubber) seals, as described in Reactor Assembly (Unit 1/3) (Ref. 4) and Reactor Vessel Disassembly and Reassembly (Ref. 5). Therefore, the SFP gate seals are not a consideration during an ELAP.
Protected Area and Vital Area Access BFN Nuclear Security maintains available, a Power Independent Alternate Power source ensuring that Security attributes can be maintained during a loss of all Plant Off-Site and Page 63 of 96
Safety Functions Support (Section 20) BWR Portable Equipment Phase 2 On-Site AC power. If Nuclear Securitys alternate power source is lost, then Nuclear Security has compensatory plans ready with actions prioritized. These plans are developed to continue site protective measures and support security related elements of an emergency response, including access to Plant Vital Areas through Security Locks and management of the Protected Area Vehicle Barrier System. In addition to these security compensatory plans, FLEX procedures will be screened for security related impediments and where applicable added measures will be afforded to ensure prompt implementation of a given strategy.
Details:
(Section 20a) Confirm that procedure/guidance exists or will be developed to support Provide a brief implementation description of Procedures /
Strategies /
Guidelines Browns Ferry Nuclear Plant will utilize the industry developed guidance from the Owners Groups, EPRI and NEI Task team to develop site specific procedures or guidelines to address the criteria in NEI 12-06. These procedures and/or guidelines will support the existing symptom based command and control strategies in the current EOIs (Open Item, OI 17).
(Section 20b) List modifications Identify modifications No modifications are required to support implementation of Phase 2 portable equipment.
Modifications that are required will be described based upon future design reviews that are controlled by the utility Standard Programs and Processes (SPPs).
(Section 20c) Key List instrumentation credited for this coping evaluation phase.
Parameter None (Section 20d) Storage / Protection of Equipment :
Describe storage / protection plan or schedule to determine storage requirements Seismic List how equipment is protected or scheduled to protect Portable equipment, maintained in the FESB, and connection points required to implement this Page 64 of 96
Safety Functions Support (Section 20) BWR Portable Equipment Phase 2 FLEX strategy will be designed to meet or exceed BFNP design basis Safe Shutdown Earthquake (SSE) protection requirements Flooding List how equipment is protected or scheduled to protect Note: if stored below current flood level, then ensure procedures exist to move equipment prior to exceeding flood level.
Portable equipment required to implement this FLEX strategy will be maintained in the FESB, which is sited in a suitable location that is above the Probable Maximum Flood (PMF) level and, as such, is not susceptible to flooding from any source. FLEX equipment deployment paths maintain a minimum elevation of 565', Mean Sea Level (MSL). Plant shutdown is required when river level reaches 558' MSL in accordance with 0-AOI-100-3 (Ref. 1a). Updated Final Safety Analysis Report (UFSAR) Section 2.4A Figure 16 (Ref. 3ai) shows that more than 5 days will elapse in a rising flood sequence between river elevation 558' MSL and 565' MSL.
Severe Storms with List how equipment is protected or scheduled to protect High Winds Portable equipment required to implement this FLEX strategy will be maintained in the FESB, which is designed to meet or exceed the licensing basis high wind hazard for BFNP, Snow, Ice, and List how equipment is protected or scheduled to protect Extreme Cold The FESB will be evaluated for snow, ice, and extreme cold temperature effects and heating will be provided as required to assure no adverse effects on the FLEX equipment. The FESB will have a stand-alone HVAC system.
High Temperatures List how equipment is protected or scheduled to protect The FESB will be evaluated for high temperature effects and ventilation will be provided as required to assure no adverse effects on the FLEX equipment. The FESB will have a stand-alone HVAC system.
(Section 20e) Deployment Conceptual Design (Attachment 3 contains Conceptual Sketches)
Strategy Modifications Protection of connections Identify strategy Identify modifications Identify how the connection is including how the protected Page 65 of 96
Safety Functions Support (Section 20) BWR Portable Equipment Phase 2 equipment will be deployed to the point of use.
480v FLEX DGs and Elevated ramps for staging Portable generators will be stored 4kv FLEX Support DGs areas may be necessary for in the FESB. The FESB shall be will be stored in the flood conditions. protected from all events listed in FESB Section 1.
References:
- 1. Abnormal Operating Instructions (AOIs)
- a. 0-AOI-100-3, Flood Above Elevation 558'
- 2. AREVA Engineering Information Record Document No.: 51-9198045-000, Browns Ferry Post Fukushima FLEX Response Evaluation
- 3. Browns Ferry Nuclear Plant (BFNP) Updated Final Safety Analysis Report (UFSAR)
- a. Section 2.4A
- i. Figure 16 (Amendment 25)
- b. Section 5-5.3, 0-47E200-2 & 3-47E200-11
- 4. GEK-779 Volume II, GEK-9646A, Reactor Assembly (Unit 1/3), GEK-9646B (U2)
- 5. MSI-0-001-VSL001, Reactor Vessel Disassembly and Reassembly, section 7.16
- 8. NRC Open Item 3.2.4.5.A from the BFN Interim Safety Evaluation (ADAMS Document ML13225A541)
Notes:
None Page 66 of 96
Safety Functions Support (Section 21) BWR Portable Equipment Phase 3 Provide a general description of the coping strategies using Phase 3 equipment including modifications that are proposed to maintain and/or support safety functions. Identify methods and strategy (ies) utilized to achieve coping times.
Main Control Room Habitability The primary and secondary strategies for cooling the MCR are the same in Phase 3 as for Phase 2.
Other Support Requirements Other areas of support required in Phase 3 are the same as described in the Phase 2 section of Safety Functions Support section.
References:
- 2. Browns Ferry Post Fukushima FLEX Response Evaluation, 91-9198045-000 Details:
(Section 21a) Provide a Confirm that procedure/guidance exists or will be developed to brief description of support implementation Procedures / Strategies /
Guidelines See Phase 2 discussion, section 20 (Section 21a) Provide a List modifications brief description of Procedures / Strategies /
Guidelines See Phase 2 discussion, section 20 (Section 21c) Key List instrumentation credited or recovered for this coping Containment evaluation.
Parameters See Phase 2 discussion, section 20 (Section 21d) Deployment Conceptual Design (Attachment 3 contains Conceptual Sketches)
Page 67 of 96
Safety Functions Support (Section 21) BWR Portable Equipment Phase 3 Strategy Modifications Protection of connections Identify strategy including Identify modifications Identify how the how the equipment will be connection is protected deployed to the point of use.
See Phase 2, Safety See Phase 2, Safety Functions See Phase 2, Safety Functions Support Support Functions Support
References:
- 1. AREVA Engineering Information Record Document No.: 51-9198045-000, Browns Ferry Post Fukushima FLEX Response Evaluation
None Page 68 of 96
(Section 22) BWR Portable Equipment Phase 2 Performance Use and (potential / flexibility) diverse uses Criteria Maintenance (Open Item, OI 13)
List portable Core Containment SFP Instrumentation Accessibility Maintenance / PM equipment (1) requirements Four FLEX Low X X X 5000 gpm Will follow EPRI Pressure Pumps, 150 psig template requirements FLPP Four Floating X X X 5,000 gpm Will follow EPRI Booster Pumps, 50 ft lift capacity template requirements FLBP Two 4160 V FLEX X X X X 4160v Will follow EPRI Generators 1.1 MW template requirements Two 480 V FLEX X X X X 480 V Will follow EPRI Generators 850 KW template requirements Hoses, adapters and X X X X As required to Will follow EPRI connectors implement template requirements strategies Two Diesel Transfer X X X 200 gpm Will follow EPRI Pumps Diesel driven template requirements Two sets of Cables X X X X X N/A Will follow EPRI for connecting template requirements portable generators Six Portable X X X X X 120V TBD, cfm as Will follow EPRI ventilation fans specified in design template requirements studies Two Tow Vehicles X X X X X 5500 series, 4wd, Will follow EPRI with bed mounted capable of on-site template requirements fuel tank and fuel transport of 14,000 transfer capability. Gross Vehicle (Deployment of Weight (GVW)
FLEX Equipment trailer and fuel and Fuel transfer with 500 Transfer). These gallon truck bed vehicles will be mounted fuel tank equipped with and fuel transfer scraper blades pump.
that will be capable of snow and ice removal.
Two Compact Track X Will be equipped with Loader - CAT a bucket, forks and a 299D (XHP) or grapple.
similar.
Page 69 of 96
(Section 23) BWR Portable Equipment Phase 3 Performance Criteria Use and (potential / flexibility) diverse uses Notes (Open Item, OI 13)
List portable Core Containment SFP Instrumentation Accessibility equipment Low Pressure FLEX X X X 5000 gpm Will follow EPRI template Pumps 150 psig requirements X X X 5,000 gpm Floating Booster Will follow EPRI template 50 ft Lift Pumps requirements 150 ft tether Medium Voltage X X X X X 4kv Will follow EPRI template Generators 1.1MW requirements Low Voltage X X X X 480 V Will follow EPRI template Generators 850 KW requirements X X X X As required Hoses, adapters and to Will follow EPRI template connectors implement requirements strategies Diesel Transfer X X X X 200 gpm Will follow EPRI template Pumps requirements Portable ventilation X X X X 5,000 cfm Will follow EPRI template fans requirements 480 V Air X X X 200 cfm Will follow EPRI template Compressors 100 psig requirements X X X Capacity Mobile Water TBD, Will follow EPRI template Purification Unit Reseverse requirements Osmosis Page 70 of 96
(Section 24) Phase 3 Response Equipment/Commodities Item Notes Radiation Protection Equipment Existing Radiation Protection equipment is adequate to address expected conditions during an event x Survey instruments x Dosimetry x Off-site monitoring/sampling x Radiological counting equipment x Radiation protection supplies x Equipment decontamination supplies x Respiratory protection Commodities Each site will maintain MREs, potable water and sanitation supplies to accommodate the intended site complement of personnel for a x Food minimum of 7 days x Meals Ready to Eat (MRE) x Microwavable Meals x Potable water x Sanitation Fuel Requirements An adequate site fuel supply and strategy exists. Fuel bladders will be delivered via the Regional Response Center x Diesel Fuel x Diesel Fuel Bladders Heavy Equipment The current strategy includes a 4 wheel drive equipment tow vehicles, various trailers for transporting supporting equipment, and multiple x Transportation equipment compact track type loaders for debris removal.
x 4 wheel drive tow vehicle x Debris clearing equipment Communications Equipment Satellite phones have been purchased and issued to each site. Portable radios already exist at each site x Satellite Phones x Portable Radios Portable Interior Lighting Provisions have been included in the strategies to store personnel lighting and batteries in a protected facility x Flashlights x Headlamps x Batteries Portable Exterior Lighting Strategies include provisions and protection for battery powered light stands with additional diesel driven light units delivered from the x Light units with diesel generator Regional Response Center Personnel equipment Strategies include hand tools as part of the protective facility storage items. These include chain saws, rigging equipment and personnel x Tools protective equipment including arc flash protection equipment x Gloves, etc.
Page 71 of 96
(Section 25) Attachments LIST OF ATTACHMENTS INDEX 1A. Sequence of Events Timeline 1B. NSSS Significant Reference Analysis Deviation Table
- 2. Milestones
- 3. Conceptual Sketches
- 4. List of Acronyms and Equipment Designators
- 5. List of Open Items Page 72 of 96
Attachment 1A, Sequence of Events Timeline Time Remarks /
Action Constraint Applicability item Elapsed Time Action Y/N 5 1 T- ~198 hours For floods, plant shutdown begins when river level N Plant meets required reaches 558' and it is predicted that level will exceed shutdown criteria 565, per procedure AOI-100-3. FLEX deployment approximately 190+
begins. hours before design basis peak flood level is reached (for FLEX, this is assumed to be exceeded).
2 T -186 hours For Floods, the plant is now is in cold shutdown. N 3 T-72 hours Flood waters reach plant grade level, FLEX pumps and Y Based on design basis portable generators (4kv and 480v) deployment must be flood.
complete.
Because the there is sufficient warning time for this condition, extra resources will be available and this time constraint will be readily achieved.
4 T-0 This is the point at which a DBF level would be N/A For information only reached.
5 Instructions: Provide justification if No or NA is selected in the remarks column.
If yes, include technical basis discussion as required by NEI 12-06 section 3.2.1.7 Page 73 of 96
Attachment 1A, Sequence of Events Timeline Time Remarks /
Action Constraint Applicability item Elapsed Time Action Y/N 5 5 T-0 All offsite power, and normal access to the ultimate heat N/A All 3 units are sink is lost - Phase 1 Commences assumed to have been operating at 100 percent rated thermal power for at least 100 days or have just been shut down from such a power history as required by plant procedures in advance of the impending event. For floods, FLEX deployment would have already been complete and the units would be at cold shutdown.
For information only.
6 T< 5 secs MSIVs isolate (for events where plant is initially in N/A Design basis response Mode 1). to loss of offsite power. For information only.
7 T+30 secs High Pressure Coolant Injection (HPCI) and RCIC N/A Design basis - Event achieve full flow. After HPCI and RCIC recover RPV initiated based on level, HPCI will be secured and RCIC will be the preliminary estimates primary system for RPV level control. When HPCI is (and assumed that secured, Operators will be directed (a change to the these valves are not SBO procedure to shift HPCI suction to the suppression operated after the first pool from the MCR. hour to maintain battery life for 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> (Open Item, OI 6). Response to loss of offsite power.
8 T + 20 minutes RPV depressurization starts at 20 minutes by a rate of Y Requirement of 90°F/hr, unless the EOIs permit a rate of 100°F/hr. Abnormal Operating Instruction for SBO, 0-100-AOI-3 and EOI-1, RPV Pressure Control.
Operators are effectively trained to carry out this action with minimal operator action.
Page 74 of 96
Attachment 1A, Sequence of Events Timeline Time Remarks /
Action Constraint Applicability item Elapsed Time Action Y/N 5 9 T<1 hours Dispatch personnel to start deployment of the applicable N FLEX Pumping FLEX Pumping Systems (Note: the FLEX Pumping Systems should be Systems will have already been deployed for a flood available for service event (see Item 2). Direction to deploy the FLEX by T+6 hours.
Pumping Systems will be contained in site procedures.
10 T<1 hours Dispatch personnel to start deployment of the 480v N 480v FLEX DG FLEX DG. (Note: the 480v FLEX DG will have already should be available been deployed for a flood event (see Item 2). Direction for service by T+7 to deploy the 480v FLEX generators will be contained hours.
in site procedures.
11 T<1 hour FLEX procedures are entered. Cooldown is continued Y New EPG Rev. 3 to a final pressure of approximately 150 psig - 250 psig. when steam driven (Cooldown will be complete for flood events) equipment is neeed to ensure adeqyate core cooling. (TVA will determine if and when manual actions are required to support continued use of Main Steam Relief Valves (MSRVs.))
Operators are effectively trained to carry out this action with minimal operator action.
12 T+< 1 hours1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> Commence load shedding of non-essential vital DC N Must be performed loads. prior to T+4 hours to extend vital battery life to T+8 hours 13 T+>2 hours Unit is being maintained above 150 psig, but as low as N New procedure reasonably achievable (having started a cooldown guidance based on depressurization at item 8). analysis not to emergency depressurize when RCIC is the only vessel makeup Page 75 of 96
Attachment 1A, Sequence of Events Timeline Time Remarks /
Action Constraint Applicability item Elapsed Time Action Y/N 5 14 T<4 hours DC load shedding of vital DC loads must be complete. Y Battery life is now extended toT+8 hours.
This action is performed on equipment in close proximity to each other and will be adequately labeled to allow easy identification.
15 T<6 hours Anticipatory venting of the containment via the Torus Y Preliminary MAAP hardened vent will commence. Preliminary MAAP analysis for a single analysis indicates that Torus temperature will be unit indicates that maintained <240 degrees and Containment pressure will Torus temperature peak at <35 psig for BFN, for a single unit only. TVA will be maintained expects to transmit a request for relaxation of full <240 degrees and compliance with NRC Order EA-12-049 until a severe Containment pressure accident capable vent is fully installed in accordance will peak at <35.
with NRC Order EA-13-109 is implemented for BFN, Units 2 and 3. BFN Unit will reach full compliance with Requires minimal EA-12-049 and EA-13-109 within the same schedule operator action.
timeframe.
16 T<6 hours 480v FLEX generator is deployed and connected to the Y Pre-staging of cable safety related battery charger for each unit. Battery and equipment to charging commences. allow connection to the charger will be performed. Further verification of this time constraint will be performed when equipment is onsite.
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Attachment 1A, Sequence of Events Timeline Time Remarks /
Action Constraint Applicability item Elapsed Time Action Y/N 5 17 T+6 hours FLEX Pumping Systems are deployed for service with Y FLEX Pumps should hoses aligned to provide RPV & SFP cooling. be available prior to reaching 240 degrees Torus water temperature, in case RCIC operation becomes unreliable or unavailable.
Based on training and testing performed with these pumps by TVA personnel this is the current best estimate.
Further verification will be performed when the augmented suction lift pumps arrive onsite.
18 T+7 hours EECW aligned to RCIC oil cooler (requires Y Time to exceed 240 modification) before temperature of the suppression degrees F comes from pool is in far excess of 240 degrees F. EECW is initial MAAP analysis supplied by FPS1. runs.
Based on having FPS in service and aligned at T+6 hours, an additional hour to align the cooler has been deemed sufficient. As the DCN is further developed and more MAAP cases are run, this time may change.
19 T+7 hours x Transition to Phase 2 of FLEX implementation for N Symptom based time RPV level control may commence. limit.
x Once low pressure injection is available via the FLEX Pumping System, RCIC may be removed from service as deemed appropriate, based on plant conditions. MSRVs (or HPCI) would be utilized to depressurize the RPV.
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Attachment 1A, Sequence of Events Timeline Time Remarks /
Action Constraint Applicability item Elapsed Time Action Y/N 5 20 T>12 hours 4kv FLEX Support Diesel Generators are deployed N They would be used and connected. The 4kv safety related distribution to energized the system is available for service. (This time may safety related 4kv change as DCN work progresses and connection distribution system strategy is verified) and energize loads such as 120v ac instrumentation, ventilation, pump motors and motor operated valves.
21 T+12 - 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> Sustain coping by maintaining diesel equipment N NEI 12-06 section fueled and in service 3.2.1.7 applicable.
22 T+>20 hours Add water as required to the SFP from the river Y Time critical at water using FLEX Pumping System(s), as required. level based on time to boil, beginning at the Tech Spec limit of 150 degrees.
Based on training and testing performed with these pumps by TVA personnel this is the current best estimate.
Further verification will be performed when the augmented suction lift pumps arrive onsite.
23 T+24 - 72 FLEX equipment will arrive from the RRC and N Adequate coping hours will be stored at staging area B capability exists without supplementation from the RRC. The FLEX equipment received from the RRC will aid in recovery and provide equipment reliability.
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Attachment 1A, Sequence of Events Timeline Time Remarks /
Action Constraint Applicability item Elapsed Time Action Y/N 5 24 T + 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> Manual actions to prevent excessive hydrogen Y The calculation of accumulation in battery rooms if ventilation is not battery room restored. hydrogen generation determined that hydrogen levels will not reach 2%
until 29.9 hours1.041667e-4 days <br />0.0025 hours <br />1.488095e-5 weeks <br />3.4245e-6 months <br /> (Open Item, OI 6).
Adequate resources will be available during this timeframe to supplement the onsite resources.
25 T+24 hours Manual actions to restore ventilation (if normal Y Adequate resources ventilation is not restored) by opening doors, will be available portable fans, etc (Open Item, OI 13). during this timeframe to supplement the onsite resources.
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Attachment 1B NSS Significant Reference Analysis Deviation Table NEDC 33771P, GEH Evaluation of FLEX Implementation Guidelines Item Parameterofinterest NEDCvalue NEDCpage Plant Gapanddiscussion
(NEDC33771PRevision0, applied
December2012) value SuppressionPoolTemperature 86°F 17 95°F 1 Ventsize 12 D9,D8,43,44, 14 2 Gaps and Discussion:
- 1. The thermal hydraulic analysis for the BFNP suppression pool shall be based on an initial temperature of 95°F (BFN TS limit).
- 2. The existing BFNP HCVS system is a 14 nominal pipe diameter. The existing configuration has a documented analysis based on vent size.
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Attachment 2 Milestones Original Target Activity Revised Target Activity Date Status Completion Date Submit Overall Integrated Plan February 2013 Complete Submit 6 Month Updates:
Update 1 August 2013 Complete Update 2 February 2014 Complete Update 3 August 2014 Complete Update 4 February 2015 Not Started Update 5 August 2015 Not Started Update 6 February 2016 Not Started Update 7 August 2016 Not Started FLEX Strategy Evaluation March 2014 Complete Unit 1 - Validation of connection points for FLEX Phase 2 & 3 via November 2016 Not Started walkthrough or demonstration.
(Graded approach)
Unit 2 - Validation of connection points for FLEX Phase 2 & 3 via April 2015 Not Started walkthrough or demonstration.
(Graded approach)
Unit 3 - Validation of connection points for FLEX Phase 2 & 3 via April 2016 Not Started walkthrough or demonstration.
(Graded approach)
Perform Staffing Analysis January 2015 Not Started December 2014 Modifications:
Modifications Evaluation March 2014 Complete Unit 1 N-1 Walkdown October 2014 Not Started Unit 1 Design Engineering November 2014 Started Unit 1 Implementation Outage October 2016 Not Started November 2016 Unit 2 N-1 Walkdown March 2013 Complete Unit 2 Design Engineering November 2014 Started Unit 2 Implementation Outage April 2015 Not Started Unit 3 N-1 Walkdown March 2014 Complete Unit 3 Design Engineering November 2014 Started Unit 3 Implementation Outage March 2016 Not Started April 2016 Page 81 of 96
Attachment 2 Milestones Original Target Activity Revised Target Activity Date Status Completion Date Storage:
Storage Design Engineering August 2014 Complete Storage Implementation November 2015 Started April 2015 FLEX Equipment:
Procure On-Site Equipment January 2015 Started Develop Strategies with RRC June 2014 Started January 2015 Install Off-Site Delivery May 2015 Started April 2015 Station Procedures:
BWROG issues FSG April 2014 Complete guidelines Create Browns Ferry FSGs March 2015 Started April 2015 Create Maintenance March 2015 Not Started April 2015 Procedures Training:
Develop Training Plan September 2014 Not Started January 2015 Implement Training January 2015 Not Started February 2015 Unit 1 FLEX Implementation November 2016 Not Started Unit 2 FLEX Implementation May 2015 Not Started April 2015 Unit 3 FLEX Implementation April 2016 Not Started Full Site FLEX Implementation November 2016 Not Started Submit Completion Report December 2016 Not Started Page 82 of 96
Attachment 3 Conceptual Sketches Index Figure 1A Electrical Diagram for FLEX Strategy - 480v FLEX Generator and Spare Figure 1B Simplified Diagram for FLEX Strategy - 4kv FLEX Support Generators Figure 2A Deployment of low pressure FLEX Pumping Systems - normal level or loss of dam Figure 2B Deployment of low pressure FLEX Pumping Systems - flood conditions Figure 3A Deployment routes for FLEX equipment Figure 3B FLEX Deployment Overview Figure 4 Overview of RRC Deployment Paths Figure 5 FLEX Pumping System Page 83 of 96
Attachment 3 Conceptual Sketches
Figure1ASimplifiedElectricalDiagramfor480vFLEXGeneratorStrategy(stillunder
evaluation)
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Attachment 3 Conceptual Sketches Emergency Diesel Generator output cables (Plant safety related DGs). Conceptual, other connection options are being evaluated.
Figure1BSimplifiedElectricalDiagramfor4160vFLEXSupportGeneratorStrategy (Still under evaluation)
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Attachment 3 Conceptual Sketches
Figure2AFLEXPumpDeploymentforNormalLevelorLossofDam Page 86 of 96
Attachment 3 Conceptual Sketches
Figure2BFLEXPumpDeploymentforFloodMode Page 87 of 96
Attachment 3 Conceptual Sketches
Figure3ADeploymentroutesforFLEXequipment
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Atttachment 3 Concepptual Sketcches Paage 89 of 96
Attachment 3 Conceptual Sketches
Figure4-OverviewofRRCDeploymentPaths Page 90 of 96
Attachment 3 Conceptual Sketches
Figure5-FLEXPumpingSystem(InformationOnly-Thesearevendorphotos)
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Attachment 4 List of Acronyms and Equipment Designators
AOI Abnormal Operating Instruction AOV Air Operated Valve ADS Automatic Depressurization System BDBEE Beyond-Design-Basis External Events BDBF Beyond-Design-Basis Flood BWR Boiling Water Reactor BWROG BWR Owners Group CILRT Containment Integrated Leak Rate Test CIV Containment Isolation Valve CRD Control Rod Drive CS Core Spray CST Condensate Storage Tank DBE Design Basis Earthquake / Design Baseline Evaluation DBF Design Basis Flood DG Diesel Generator ECCS Emergency Core Cooling System EDG Emergency Diesel Generator EECW Emergency Equipment Cooling Water ELAP Extended Loss of AC Power EOI Emergency Operating Instruction EOP Emergency Operating Procedure EPG BWROG Emergency Procedure Guideline FESB Flexible Equipment Storage Building FLEX Flexible and Diverse Coping Mitigation Strategies FPCCU Fuel Pool Cooling and Cleanup System FSAR Final Safety Analysis Report FSG Flex Support Guidelines GEH GE Hitachi HCTL Heat Capacity Temperature Limit (for Torus/Suppression Pool)
HCVS Hardened Containment Vent System HPCI High Pressure Coolant Injection HTX Heat Exchanger HVAC Heating Ventilation Air Conditioning ICS Integrated Computer System ILRT Integrated Leak Rate Test kVA KiloVolt-Ampere LUHS Loss of Ultimate Heat Sink MAAP Modular Accident Analysis Program MCR Main Control Room MCRHZ Main Control Room Habitability Zone MELB Moderate Energy Line Break MRE Meals Ready to Eat MSL Mean Sea Level Page 92 of 96
Attachment 4 List of Acronyms and Equipment Designators MSRV Main Steam Relief Valve NEI Nuclear Energy Institute NPSH Net Positive Suction Head OBE Operating Basis Earthquake OPS Operations Department PMF Probable Maximum Flood PCP-lim Primary Containment Pressure Limit PSP Pressure Suppression Pressure (function of Primary Containment Water Level)
PWR Pressurized Water Reactor RBCCW Reactor Building Closed Cooling Water RCIC Reactor Core Isolation Cooling RHR Residual Heat Removal RHRSW RHR Service Water RHVS Reliable Hardened Vent System RPV Reactor Pressure Vessel RRC Regional Response Center RWCU Reactor Water Clean Up SAFER Strategic Alliance for FLEX Emergency Response SBO Station Blackout SFP Spent Fuel Pool SGTS Standby Gas Treatment System SHEX SUPERHEX computer code SOV Solenoid Operated Valve SRV Safety Relief Valve SSC System, Structure, or Component SSE Safe Shutdown Earthquake UFSAR Updated Final Safety Analysis Report UHS Ultimate Heat Sink Equipment Designators DieselGenerators FMDG-FLEXMediumVoltageGenerator(FMDG1 4160VFLEX1.1MWaircooled,turbinepowered
andFMDG2) Generators
FLDG-FLEXLowVoltageGenerator(FLDG1and 480VFLEX850KWaircooled,turbinepowered
FLDG2) Generators
Pumps,ifwritteninstrategyasdeployed/used
FPS-FLEXPumpingSystem(FPS1/2/3/4) FLEXlowpressuredieseldrivenpumps+Flex
floatingboosterpumps
FLPP1,FLPP2,FLPP3,FLPP4 FLEXlowpressurepump
FLBP1,FLBP2,FLBP3,FLPB4 FLEXfloatingboosterpump
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Attachment 5 List of Open Items
- 1. Flood and seismic re-evaluations pursuant to the 10 CFR 50.54(f) letter of March 12, 2012 are not completed and therefore not assumed in this submittal. As the re-evaluations are completed, appropriate issues will be entered into the corrective action system and addressed
- 2. Liquefaction of haul routes for FLEX will be analyzed from Staging Area B to Staging Area A. Also, an evaluation will be conducted of haul routes from Staging Area D and Staging Area C to Staging Area B.
- 3. TVA will confirm that they have enough fuel onsite for the first 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. A diesel fuel storage and refueling plan also has to be developed.
- 4. BFNP will evaluate MSRV qualification against the predicted containment response with FLEX implementation to ensure there will be sufficient DC bus voltage and pneumatic pressure to operate the MSRVs throughout Phase 1 and Phase 2.
Closed - Based on data contained within BFN EQ Binder, BFNEQ-SOL-009 D4, which demonstrated that MRSV Solenoid & Air Assembly can operate at temperatures < 340 degrees F, operating pressure at least 45 psig > than containment pressure and DC voltage in the range of 212 to 276 vDC.
- 5. A reference source for the plant operators will be developed that provides approaches to obtaining necessary instrument readings to support the implementation of the coping strategy (NE 12-06, Section 3.2.1.1 0). This reference source should include control room and non-control room readouts and should also provide guidance on how and where to measure key instrument readings at containment penetrations, where applicable, using a portable instrument (e.g., a Fluke meter). Such a resource could be provided as an attachment to the plant procedures/guidance. Guidance will include critical actions to perform until alternate indications can be connected and on how to control critical equipment without associated control power.
- 6. Validate the preliminary Battery studies that were performed to ensure appropriate battery life will be available with regards to the overall FLEX strategies. Ensure that buildup of hydrogen is considered and mitigated appropriately.
- 7. BFNP will take actions as necessary to assure RCIC can operate at elevated temperatures.
- 8. Perform modifications, as necessary, to ensure that RCIC is seismically robust.
- 9. Develop and perform the design modifications identified in the FLEX strategy document to permit the timely and safe connection of the FLEX and RRC equipment during the adverse conditions encountered during these beyond-design-basis events.
- 10. Design and construct a Flexible Equipment Storage Building, located above the probable maximum flood level, which is adequately protected from the hazards listed in Section 1.
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Attachment 5 List of Open Items The storage facility(s) will be used to store support equipment and items, including the four FLEX Pumping Systems.
- 11. Modify currently installed hardened wetwell vent to install backup pneumatic supply or provided procedural guidance for manual operation, to allow use within current design limits.
- 13. Determine the design specifications for FLEX equipment yet to be ordered, such as the Six Portable ventilation fans, the Mobile Water Purification Unit, debris removal equipment for the FLEX Equipment Haul path and piping for the FLEX low pressure pumps.
- 14. Deployment strategies and deployment routes will be assessed for impact due to identified hazards and guidance developed/provided to ensure that 1) sufficient area is available for deployment, 2) haul paths remain accessible without interference from outage equipment during refueling outages and 3) deployment locations for the pumps, including ramps, winches or other transfer assemblies, as appropriate to deploy all pumps and hoses within the 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> Phase 1 coping interval.
- 15. Detailed staffing studies based on the procedures/guidance developed.
- 16. Validation of the time lines for the various strategies.
- 17. Browns Ferry Nuclear Plant (BFNP) will utilize the industry developed guidance from the Owners Groups, EPRI and NEI Task team to develop site specific procedures or guidelines to address the criteria in NEI 12-06. These procedures and/or guidelines will support the existing symptom based command and control strategies in the current EOIs.
- 18. New training of general station staff and EP will be performed prior to the first BFNP unit design implementation outage. These programs and controls will be implemented in accordance with the Systematic Approach to Training.
- 19. TVA will establish a contract with the Strategic Alliance for FLEX Emergency Response (SAFER) team. A local assembly area must also be established by SAFER and TVA for equipment moved from the Regional Response Center (RRC) to BFNP.
Closure: Open Item should be closed. Refer to Section 9 of the OIP. Reference AREVA NP Inc., Engineering Information Record, Document No.: 51 - 9213690 - 001, SAFER Response Plan Master Templates
- 20. Evaluate different strategies to allow removal of water from the Suppression Pool.
Determine if any modifications are required and what strategies are deemed feasible.
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Attachment 5 List of Open Items
- 21. Abnormal operating procedure, AOI-100-9, Turbine Building Internal Flooding, provides the symptoms and operator actions to be taken for this condition. During development of procedures to support FLEX strategies, adequate guidance will be given to operators to ensure their travel paths avoid these areas.
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